## Appendix B Summary of Library Facilities

This appendix is a complete list of the facilities declared within the header files supplied with the GNU C Library. Each entry also lists the standard or other source from which each facility is derived, and tells you where in the manual you can find more information about how to use it.

`long int a64l (const char *`string`)`
  `stdlib.h` (XPG): Encode Binary Data.
`void abort (void)`
  `stdlib.h` (ISO): Aborting a Program.
`int abs (int` number`)`
  `stdlib.h` (ISO): Absolute Value.
`int accept (int` socket`, struct sockaddr *`addr`, socklen_t *`length_ptr`)`
  `sys/socket.h` (BSD): Accepting Connections.
`int access (const char *`filename`, int` how`)`
  `unistd.h` (POSIX.1): Testing File Access.
`ACCOUNTING`
  `utmp.h` (SVID): Manipulating the Database.
`double acos (double` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`float acosf (float` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`double acosh (double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`float acoshf (float` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double acoshl (long double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double acosl (long double` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`int addmntent (FILE *`stream`, const struct mntent *`mnt`)`
  `mntent.h` (BSD): mtab.
`int adjtime (const struct timeval *`delta`, struct timeval *`olddelta`)`
  `sys/time.h` (BSD): High-Resolution Calendar.
`int adjtimex (struct timex *`timex`)`
  `sys/timex.h` (GNU): High-Resolution Calendar.
`AF_FILE`
  `sys/socket.h` (GNU): Address Formats.
`AF_INET`
  `sys/socket.h` (BSD): Address Formats.
`AF_INET6`
  `sys/socket.h` (IPv6 Basic API): Address Formats.
`AF_LOCAL`
  `sys/socket.h` (POSIX): Address Formats.
`AF_UNIX`
  `sys/socket.h` (BSD, Unix98): Address Formats.
`AF_UNSPEC`
  `sys/socket.h` (BSD): Address Formats.
`int aio_cancel (int` fildes`, struct aiocb *`aiocbp`)`
  `aio.h` (POSIX.1b): Cancel AIO Operations.
`int aio_cancel64 (int` fildes`, struct aiocb64 *`aiocbp`)`
  `aio.h` (Unix98): Cancel AIO Operations.
`int aio_error (const struct aiocb *`aiocbp`)`
  `aio.h` (POSIX.1b): Status of AIO Operations.
`int aio_error64 (const struct aiocb64 *`aiocbp`)`
  `aio.h` (Unix98): Status of AIO Operations.
`int aio_fsync (int` op`, struct aiocb *`aiocbp`)`
  `aio.h` (POSIX.1b): Synchronizing AIO Operations.
`int aio_fsync64 (int` op`, struct aiocb64 *`aiocbp`)`
  `aio.h` (Unix98): Synchronizing AIO Operations.
`void aio_init (const struct aioinit *`init`)`
  `aio.h` (GNU): Configuration of AIO.
`int aio_read (struct aiocb *`aiocbp`)`
  `aio.h` (POSIX.1b): Asynchronous Reads/Writes.
`int aio_read64 (struct aiocb64 *`aiocbp`)`
  `aio.h` (Unix98): Asynchronous Reads/Writes.
`ssize_t aio_return (struct aiocb *`aiocbp`)`
  `aio.h` (POSIX.1b): Status of AIO Operations.
`ssize_t aio_return64 (struct aiocb64 *`aiocbp`)`
  `aio.h` (Unix98): Status of AIO Operations.
`int aio_suspend (const struct aiocb *const` list`[], int` nent`, const struct timespec *`timeout`)`
  `aio.h` (POSIX.1b): Synchronizing AIO Operations.
`int aio_suspend64 (const struct aiocb64 *const` list`[], int` nent`, const struct timespec *`timeout`)`
  `aio.h` (Unix98): Synchronizing AIO Operations.
`int aio_write (struct aiocb *`aiocbp`)`
  `aio.h` (POSIX.1b): Asynchronous Reads/Writes.
`int aio_write64 (struct aiocb64 *`aiocbp`)`
  `aio.h` (Unix98): Asynchronous Reads/Writes.
`unsigned int alarm (unsigned int` seconds`)`
  `unistd.h` (POSIX.1): Setting an Alarm.
`void * alloca (size_t` size`)`
  `stdlib.h` (GNU, BSD): Variable Size Automatic.
`int alphasort (const void *`a`, const void *`b`)`
  `dirent.h` (BSD/SVID): Scanning Directory Content.
`int alphasort64 (const void *`a`, const void *`b`)`
  `dirent.h` (GNU): Scanning Directory Content.
`tcflag_t ALTWERASE`
  `termios.h` (BSD): Local Modes.
`int ARG_MAX`
  `limits.h` (POSIX.1): General Limits.
`error_t argp_err_exit_status`
  `argp.h` (GNU): Argp Global Variables.
`void argp_error (const struct argp_state *`state`, const char *`fmt`, ...)`
  `argp.h` (GNU): Argp Helper Functions.
`int ARGP_ERR_UNKNOWN`
  `argp.h` (GNU): Argp Parser Functions.
`void argp_failure (const struct argp_state *`state`, int` status`, int` errnum`, const char *`fmt`, ...)`
  `argp.h` (GNU): Argp Helper Functions.
`void argp_help (const struct argp *`argp`, FILE *`stream`, unsigned` flags`, char *`name`)`
  `argp.h` (GNU): Argp Help.
`ARGP_IN_ORDER`
  `argp.h` (GNU): Argp Flags.
`ARGP_KEY_ARG`
  `argp.h` (GNU): Argp Special Keys.
`ARGP_KEY_ARGS`
  `argp.h` (GNU): Argp Special Keys.
`ARGP_KEY_END`
  `argp.h` (GNU): Argp Special Keys.
`ARGP_KEY_ERROR`
  `argp.h` (GNU): Argp Special Keys.
`ARGP_KEY_FINI`
  `argp.h` (GNU): Argp Special Keys.
`ARGP_KEY_HELP_ARGS_DOC`
  `argp.h` (GNU): Argp Help Filter Keys.
`ARGP_KEY_HELP_DUP_ARGS_NOTE`
  `argp.h` (GNU): Argp Help Filter Keys.
`ARGP_KEY_HELP_EXTRA`
  `argp.h` (GNU): Argp Help Filter Keys.
`ARGP_KEY_HELP_HEADER`
  `argp.h` (GNU): Argp Help Filter Keys.
`ARGP_KEY_HELP_POST_DOC`
  `argp.h` (GNU): Argp Help Filter Keys.
`ARGP_KEY_HELP_PRE_DOC`
  `argp.h` (GNU): Argp Help Filter Keys.
`ARGP_KEY_INIT`
  `argp.h` (GNU): Argp Special Keys.
`ARGP_KEY_NO_ARGS`
  `argp.h` (GNU): Argp Special Keys.
`ARGP_KEY_SUCCESS`
  `argp.h` (GNU): Argp Special Keys.
`ARGP_LONG_ONLY`
  `argp.h` (GNU): Argp Flags.
`ARGP_NO_ARGS`
  `argp.h` (GNU): Argp Flags.
`ARGP_NO_ERRS`
  `argp.h` (GNU): Argp Flags.
`ARGP_NO_EXIT`
  `argp.h` (GNU): Argp Flags.
`ARGP_NO_HELP`
  `argp.h` (GNU): Argp Flags.
`error_t argp_parse (const struct argp *`argp`, int` argc`, char **`argv`, unsigned` flags`, int *`arg_index`, void *`input`)`
  `argp.h` (GNU): Suboptions.
`ARGP_PARSE_ARGV0`
  `argp.h` (GNU): Argp Flags.
`const char * argp_program_bug_address`
  `argp.h` (GNU): Argp Global Variables.
`const char * argp_program_version`
  `argp.h` (GNU): Argp Global Variables.
`argp_program_version_hook`
  `argp.h` (GNU): Argp Global Variables.
`ARGP_SILENT`
  `argp.h` (GNU): Argp Flags.
`void argp_state_help (const struct argp_state *`state`, FILE *`stream`, unsigned` flags`)`
  `argp.h` (GNU): Argp Helper Functions.
`void argp_usage (const struct argp_state *`state`)`
  `argp.h` (GNU): Argp Helper Functions.
`error_t argz_add (char **`argz`, size_t *`argz_len`, const char *`str`)`
  `argz.h` (GNU): Argz Functions.
`error_t argz_add_sep (char **`argz`, size_t *`argz_len`, const char *`str`, int` delim`)`
  `argz.h` (GNU): Argz Functions.
`error_t argz_append (char **`argz`, size_t *`argz_len`, const char *`buf`, size_t` buf_len`)`
  `argz.h` (GNU): Argz Functions.
`size_t argz_count (const char *`argz`, size_t` arg_len`)`
  `argz.h` (GNU): Argz Functions.
`error_t argz_create (char *const` argv`[], char **`argz`, size_t *`argz_len`)`
  `argz.h` (GNU): Argz Functions.
`error_t argz_create_sep (const char *`string`, int` sep`, char **`argz`, size_t *`argz_len`)`
  `argz.h` (GNU): Argz Functions.
`void argz_delete (char **`argz`, size_t *`argz_len`, char *`entry`)`
  `argz.h` (GNU): Argz Functions.
`void argz_extract (const char *`argz`, size_t` argz_len`, char **`argv`)`
  `argz.h` (GNU): Argz Functions.
`error_t argz_insert (char **`argz`, size_t *`argz_len`, char *`before`, const char *`entry`)`
  `argz.h` (GNU): Argz Functions.
`char * argz_next (const char *`argz`, size_t` argz_len`, const char *`entry`)`
  `argz.h` (GNU): Argz Functions.
`error_t argz_replace (char **`argz`, size_t *`argz_len`, const char *`str`, const char *`with`, unsigned *`replace_count`)`
  `argz.h` (GNU): Argz Functions.
`void argz_stringify (char *`argz`, size_t` len`, int` sep`)`
  `argz.h` (GNU): Argz Functions.
`char * asctime (const struct tm *`brokentime`)`
  `time.h` (ISO): Formatting Calendar Time.
`char * asctime_r (const struct tm *`brokentime`, char *`buffer`)`
  `time.h` (POSIX.1c): Formatting Calendar Time.
`double asin (double` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`float asinf (float` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`double asinh (double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`float asinhf (float` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double asinhl (long double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double asinl (long double` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`int asprintf (char **`ptr`, const char *`template`, ...)`
  `stdio.h` (GNU): Dynamic Output.
`void assert (int` expression`)`
  `assert.h` (ISO): Consistency Checking.
`void assert_perror (int` errnum`)`
  `assert.h` (GNU): Consistency Checking.
`double atan (double` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`double atan2 (double` y`, double` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`float atan2f (float` y`, float` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`long double atan2l (long double` y`, long double` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`float atanf (float` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`double atanh (double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`float atanhf (float` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double atanhl (long double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double atanl (long double` x`)`
  `math.h` (ISO): Inverse Trig Functions.
`int atexit (void (*`function`) (void))`
  `stdlib.h` (ISO): Cleanups on Exit.
`double atof (const char *`string`)`
  `stdlib.h` (ISO): Parsing of Floats.
`int atoi (const char *`string`)`
  `stdlib.h` (ISO): Parsing of Integers.
`long int atol (const char *`string`)`
  `stdlib.h` (ISO): Parsing of Integers.
`long long int atoll (const char *`string`)`
  `stdlib.h` (ISO): Parsing of Integers.
`B0`
  `termios.h` (POSIX.1): Line Speed.
`B110`
  `termios.h` (POSIX.1): Line Speed.
`B115200`
  `termios.h` (GNU): Line Speed.
`B1200`
  `termios.h` (POSIX.1): Line Speed.
`B134`
  `termios.h` (POSIX.1): Line Speed.
`B150`
  `termios.h` (POSIX.1): Line Speed.
`B1800`
  `termios.h` (POSIX.1): Line Speed.
`B19200`
  `termios.h` (POSIX.1): Line Speed.
`B200`
  `termios.h` (POSIX.1): Line Speed.
`B230400`
  `termios.h` (GNU): Line Speed.
`B2400`
  `termios.h` (POSIX.1): Line Speed.
`B300`
  `termios.h` (POSIX.1): Line Speed.
`B38400`
  `termios.h` (POSIX.1): Line Speed.
`B460800`
  `termios.h` (GNU): Line Speed.
`B4800`
  `termios.h` (POSIX.1): Line Speed.
`B50`
  `termios.h` (POSIX.1): Line Speed.
`B57600`
  `termios.h` (GNU): Line Speed.
`B600`
  `termios.h` (POSIX.1): Line Speed.
`B75`
  `termios.h` (POSIX.1): Line Speed.
`B9600`
  `termios.h` (POSIX.1): Line Speed.
`int backtrace (void **`buffer`, int` size`)`
  `execinfo.h` (GNU): Backtraces.
`char ** backtrace_symbols (void *const *`buffer`, int` size`)`
  `execinfo.h` (GNU): Backtraces.
`void backtrace_symbols_fd (void *const *`buffer`, int` size`, int` fd`)`
  `execinfo.h` (GNU): Backtraces.
`char * basename (const char *`filename`)`
  `string.h` (GNU): Finding Tokens in a String.
`char * basename (const char *`path`)`
  `libgen.h` (XPG): Finding Tokens in a String.
`int BC_BASE_MAX`
  `limits.h` (POSIX.2): Utility Limits.
`int BC_DIM_MAX`
  `limits.h` (POSIX.2): Utility Limits.
`int bcmp (const void *`a1`, const void *`a2`, size_t` size`)`
  `string.h` (BSD): String/Array Comparison.
`void bcopy (const void *`from`, void *`to`, size_t` size`)`
  `string.h` (BSD): Copying and Concatenation.
`int BC_SCALE_MAX`
  `limits.h` (POSIX.2): Utility Limits.
`int BC_STRING_MAX`
  `limits.h` (POSIX.2): Utility Limits.
`int bind (int` socket`, struct sockaddr *`addr`, socklen_t` length`)`
  `sys/socket.h` (BSD): Setting Address.
`char * bindtextdomain (const char *`domainname`, const char *`dirname`)`
  `libintl.h` (GNU): Locating gettext catalog.
`char * bind_textdomain_codeset (const char *`domainname`, const char *`codeset`)`
  `libintl.h` (GNU): Charset conversion in gettext.
`blkcnt64_t`
  `sys/types.h` (Unix98): Attribute Meanings.
`blkcnt_t`
  `sys/types.h` (Unix98): Attribute Meanings.
`BOOT_TIME`
  `utmp.h` (SVID): Manipulating the Database.
`BOOT_TIME`
  `utmpx.h` (XPG4.2): XPG Functions.
`int brk (void *`addr`)`
  `unistd.h` (BSD): Resizing the Data Segment.
`tcflag_t BRKINT`
  `termios.h` (POSIX.1): Input Modes.
`_BSD_SOURCE`
  (GNU): Feature Test Macros.
`void * bsearch (const void *`key`, const void *`array`, size_t` count`, size_t` size`, comparison_fn_t` compare`)`
  `stdlib.h` (ISO): Array Search Function.
`wint_t btowc (int` c`)`
  `wchar.h` (ISO): Converting a Character.
`int BUFSIZ`
  `stdio.h` (ISO): Controlling Buffering.
`void bzero (void *`block`, size_t` size`)`
  `string.h` (BSD): Copying and Concatenation.
`double cabs (complex double` z`)`
  `complex.h` (ISO): Absolute Value.
`float cabsf (complex float` z`)`
  `complex.h` (ISO): Absolute Value.
`long double cabsl (complex long double` z`)`
  `complex.h` (ISO): Absolute Value.
`complex double cacos (complex double` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`complex float cacosf (complex float` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`complex double cacosh (complex double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex float cacoshf (complex float` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double cacoshl (complex long double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double cacosl (complex long double` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`void * calloc (size_t` count`, size_t` eltsize`)`
  `malloc.h`, `stdlib.h` (ISO): Allocating Cleared Space.
`char * canonicalize_file_name (const char *`name`)`
  `stdlib.h` (GNU): Symbolic Links.
`double carg (complex double` z`)`
  `complex.h` (ISO): Operations on Complex.
`float cargf (complex float` z`)`
  `complex.h` (ISO): Operations on Complex.
`long double cargl (complex long double` z`)`
  `complex.h` (ISO): Operations on Complex.
`complex double casin (complex double` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`complex float casinf (complex float` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`complex double casinh (complex double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex float casinhf (complex float` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double casinhl (complex long double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double casinl (complex long double` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`complex double catan (complex double` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`complex float catanf (complex float` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`complex double catanh (complex double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex float catanhf (complex float` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double catanhl (complex long double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double catanl (complex long double` z`)`
  `complex.h` (ISO): Inverse Trig Functions.
`nl_catd catopen (const char *`cat_name`, int` flag`)`
  `nl_types.h` (X/Open): The catgets Functions.
`int cbc_crypt (char *`key`, char *`blocks`, unsigned` len`, unsigned` mode`, char *`ivec`)`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`double cbrt (double` x`)`
  `math.h` (BSD): Exponents and Logarithms.
`float cbrtf (float` x`)`
  `math.h` (BSD): Exponents and Logarithms.
`long double cbrtl (long double` x`)`
  `math.h` (BSD): Exponents and Logarithms.
`complex double ccos (complex double` z`)`
  `complex.h` (ISO): Trig Functions.
`complex float ccosf (complex float` z`)`
  `complex.h` (ISO): Trig Functions.
`complex double ccosh (complex double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex float ccoshf (complex float` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double ccoshl (complex long double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double ccosl (complex long double` z`)`
  `complex.h` (ISO): Trig Functions.
`cc_t`
  `termios.h` (POSIX.1): Mode Data Types.
`tcflag_t CCTS_OFLOW`
  `termios.h` (BSD): Control Modes.
`double ceil (double` x`)`
  `math.h` (ISO): Rounding Functions.
`float ceilf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long double ceill (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`complex double cexp (complex double` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex float cexpf (complex float` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex long double cexpl (complex long double` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`speed_t cfgetispeed (const struct termios *`termios-p`)`
  `termios.h` (POSIX.1): Line Speed.
`speed_t cfgetospeed (const struct termios *`termios-p`)`
  `termios.h` (POSIX.1): Line Speed.
`void cfmakeraw (struct termios *`termios-p`)`
  `termios.h` (BSD): Noncanonical Input.
`void cfree (void *`ptr`)`
  `stdlib.h` (Sun): Freeing after Malloc.
`int cfsetispeed (struct termios *`termios-p`, speed_t` speed`)`
  `termios.h` (POSIX.1): Line Speed.
`int cfsetospeed (struct termios *`termios-p`, speed_t` speed`)`
  `termios.h` (POSIX.1): Line Speed.
`int cfsetspeed (struct termios *`termios-p`, speed_t` speed`)`
  `termios.h` (BSD): Line Speed.
`CHAR_BIT`
  `limits.h` (ISO): Width of Type.
`CHAR_MAX`
  `limits.h` (ISO): Range of Type.
`CHAR_MIN`
  `limits.h` (ISO): Range of Type.
`int chdir (const char *`filename`)`
  `unistd.h` (POSIX.1): Working Directory.
`int CHILD_MAX`
  `limits.h` (POSIX.1): General Limits.
`int chmod (const char *`filename`, mode_t` mode`)`
  `sys/stat.h` (POSIX.1): Setting Permissions.
`int chown (const char *`filename`, uid_t` owner`, gid_t` group`)`
  `unistd.h` (POSIX.1): File Owner.
`tcflag_t CIGNORE`
  `termios.h` (BSD): Control Modes.
`double cimag (complex double` z`)`
  `complex.h` (ISO): Operations on Complex.
`float cimagf (complex float` z`)`
  `complex.h` (ISO): Operations on Complex.
`long double cimagl (complex long double` z`)`
  `complex.h` (ISO): Operations on Complex.
`int clearenv (void)`
  `stdlib.h` (GNU): Environment Access.
`void clearerr (FILE *`stream`)`
  `stdio.h` (ISO): Error Recovery.
`void clearerr_unlocked (FILE *`stream`)`
  `stdio.h` (GNU): Error Recovery.
`int CLK_TCK`
  `time.h` (POSIX.1): Processor Time.
`tcflag_t CLOCAL`
  `termios.h` (POSIX.1): Control Modes.
`clock_t clock (void)`
  `time.h` (ISO): CPU Time.
`int CLOCKS_PER_SEC`
  `time.h` (ISO): CPU Time.
`clock_t`
  `time.h` (ISO): CPU Time.
`complex double clog (complex double` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex double clog10 (complex double` z`)`
  `complex.h` (GNU): Exponents and Logarithms.
`complex float clog10f (complex float` z`)`
  `complex.h` (GNU): Exponents and Logarithms.
`complex long double clog10l (complex long double` z`)`
  `complex.h` (GNU): Exponents and Logarithms.
`complex float clogf (complex float` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex long double clogl (complex long double` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`int close (int` filedes`)`
  `unistd.h` (POSIX.1): Opening and Closing Files.
`int closedir (DIR *`dirstream`)`
  `dirent.h` (POSIX.1): Reading/Closing Directory.
`void closelog (void)`
  `syslog.h` (BSD): closelog.
`int COLL_WEIGHTS_MAX`
  `limits.h` (POSIX.2): Utility Limits.
`size_t confstr (int` parameter`, char *`buf`, size_t` len`)`
  `unistd.h` (POSIX.2): String Parameters.
`complex double conj (complex double` z`)`
  `complex.h` (ISO): Operations on Complex.
`complex float conjf (complex float` z`)`
  `complex.h` (ISO): Operations on Complex.
`complex long double conjl (complex long double` z`)`
  `complex.h` (ISO): Operations on Complex.
`int connect (int` socket`, struct sockaddr *`addr`, socklen_t` length`)`
  `sys/socket.h` (BSD): Connecting.
`cookie_close_function`
  `stdio.h` (GNU): Hook Functions.
`cookie_io_functions_t`
  `stdio.h` (GNU): Streams and Cookies.
`cookie_read_function`
  `stdio.h` (GNU): Hook Functions.
`cookie_seek_function`
  `stdio.h` (GNU): Hook Functions.
`cookie_write_function`
  `stdio.h` (GNU): Hook Functions.
`double copysign (double` x`, double` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`float copysignf (float` x`, float` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`long double copysignl (long double` x`, long double` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`double cos (double` x`)`
  `math.h` (ISO): Trig Functions.
`float cosf (float` x`)`
  `math.h` (ISO): Trig Functions.
`double cosh (double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`float coshf (float` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double coshl (long double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double cosl (long double` x`)`
  `math.h` (ISO): Trig Functions.
`complex double cpow (complex double` base`, complex double` power`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex float cpowf (complex float` base`, complex float` power`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex long double cpowl (complex long double` base`, complex long double` power`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex double cproj (complex double` z`)`
  `complex.h` (ISO): Operations on Complex.
`complex float cprojf (complex float` z`)`
  `complex.h` (ISO): Operations on Complex.
`complex long double cprojl (complex long double` z`)`
  `complex.h` (ISO): Operations on Complex.
`void CPU_CLR (int` cpu`, cpu_set_t *`set`)`
  `sched.h` (GNU): CPU Affinity.
`int CPU_ISSET (int` cpu`, const cpu_set_t *`set`)`
  `sched.h` (GNU): CPU Affinity.
`void CPU_SET (int` cpu`, cpu_set_t *`set`)`
  `sched.h` (GNU): CPU Affinity.
`int CPU_SETSIZE`
  `sched.h` (GNU): CPU Affinity.
`cpu_set_t`
  `sched.h` (GNU): CPU Affinity.
`void CPU_ZERO (cpu_set_t *`set`)`
  `sched.h` (GNU): CPU Affinity.
`tcflag_t CREAD`
  `termios.h` (POSIX.1): Control Modes.
`double creal (complex double` z`)`
  `complex.h` (ISO): Operations on Complex.
`float crealf (complex float` z`)`
  `complex.h` (ISO): Operations on Complex.
`long double creall (complex long double` z`)`
  `complex.h` (ISO): Operations on Complex.
`int creat (const char *`filename`, mode_t` mode`)`
  `fcntl.h` (POSIX.1): Opening and Closing Files.
`int creat64 (const char *`filename`, mode_t` mode`)`
  `fcntl.h` (Unix98): Opening and Closing Files.
`tcflag_t CRTS_IFLOW`
  `termios.h` (BSD): Control Modes.
`char * crypt (const char *`key`, const char *`salt`)`
  `crypt.h` (BSD, SVID): crypt.
`char * crypt_r (const char *`key`, const char *`salt`, struct crypt_data *` data`)`
  `crypt.h` (GNU): crypt.
`tcflag_t CS5`
  `termios.h` (POSIX.1): Control Modes.
`tcflag_t CS6`
  `termios.h` (POSIX.1): Control Modes.
`tcflag_t CS7`
  `termios.h` (POSIX.1): Control Modes.
`tcflag_t CS8`
  `termios.h` (POSIX.1): Control Modes.
`complex double csin (complex double` z`)`
  `complex.h` (ISO): Trig Functions.
`complex float csinf (complex float` z`)`
  `complex.h` (ISO): Trig Functions.
`complex double csinh (complex double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex float csinhf (complex float` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double csinhl (complex long double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double csinl (complex long double` z`)`
  `complex.h` (ISO): Trig Functions.
`tcflag_t CSIZE`
  `termios.h` (POSIX.1): Control Modes.
`_CS_LFS64_CFLAGS`
  `unistd.h` (Unix98): String Parameters.
`_CS_LFS64_LDFLAGS`
  `unistd.h` (Unix98): String Parameters.
`_CS_LFS64_LIBS`
  `unistd.h` (Unix98): String Parameters.
`_CS_LFS64_LINTFLAGS`
  `unistd.h` (Unix98): String Parameters.
`_CS_LFS_CFLAGS`
  `unistd.h` (Unix98): String Parameters.
`_CS_LFS_LDFLAGS`
  `unistd.h` (Unix98): String Parameters.
`_CS_LFS_LIBS`
  `unistd.h` (Unix98): String Parameters.
`_CS_LFS_LINTFLAGS`
  `unistd.h` (Unix98): String Parameters.
`_CS_PATH`
  `unistd.h` (POSIX.2): String Parameters.
`complex double csqrt (complex double` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex float csqrtf (complex float` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`complex long double csqrtl (complex long double` z`)`
  `complex.h` (ISO): Exponents and Logarithms.
`tcflag_t CSTOPB`
  `termios.h` (POSIX.1): Control Modes.
`complex double ctan (complex double` z`)`
  `complex.h` (ISO): Trig Functions.
`complex float ctanf (complex float` z`)`
  `complex.h` (ISO): Trig Functions.
`complex double ctanh (complex double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex float ctanhf (complex float` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double ctanhl (complex long double` z`)`
  `complex.h` (ISO): Hyperbolic Functions.
`complex long double ctanl (complex long double` z`)`
  `complex.h` (ISO): Trig Functions.
`char * ctermid (char *`string`)`
  `stdio.h` (POSIX.1): Identifying the Terminal.
`char * ctime (const time_t *`time`)`
  `time.h` (ISO): Formatting Calendar Time.
`char * ctime_r (const time_t *`time`, char *`buffer`)`
  `time.h` (POSIX.1c): Formatting Calendar Time.
`char * cuserid (char *`string`)`
  `stdio.h` (POSIX.1): Who Logged In.
`int daylight`
  `time.h` (SVID): Time Zone Functions.
`DBL_DIG`
  `float.h` (ISO): Floating Point Parameters.
`DBL_EPSILON`
  `float.h` (ISO): Floating Point Parameters.
`DBL_MANT_DIG`
  `float.h` (ISO): Floating Point Parameters.
`DBL_MAX`
  `float.h` (ISO): Floating Point Parameters.
`DBL_MAX_10_EXP`
  `float.h` (ISO): Floating Point Parameters.
`DBL_MAX_EXP`
  `float.h` (ISO): Floating Point Parameters.
`DBL_MIN`
  `float.h` (ISO): Floating Point Parameters.
`DBL_MIN_10_EXP`
  `float.h` (ISO): Floating Point Parameters.
`DBL_MIN_EXP`
  `float.h` (ISO): Floating Point Parameters.
`char * dcgettext (const char *`domainname`, const char *`msgid`, int` category`)`
  `libintl.h` (GNU): Translation with gettext.
`char * dcngettext (const char *`domain`, const char *`msgid1`, const char *`msgid2`, unsigned long int` n`, int` category`)`
  `libintl.h` (GNU): Advanced gettext functions.
`DEAD_PROCESS`
  `utmp.h` (SVID): Manipulating the Database.
`DEAD_PROCESS`
  `utmpx.h` (XPG4.2): XPG Functions.
`DES_DECRYPT`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`DES_ENCRYPT`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`DESERR_BADPARAM`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`DESERR_HWERROR`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`DESERR_NOHWDEVICE`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`DESERR_NONE`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`int DES_FAILED (int` err`)`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`DES_HW`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`void des_setparity (char *`key`)`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`DES_SW`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`dev_t`
  `sys/types.h` (POSIX.1): Attribute Meanings.
`char * dgettext (const char *`domainname`, const char *`msgid`)`
  `libintl.h` (GNU): Translation with gettext.
`double difftime (time_t` time1`, time_t` time0`)`
  `time.h` (ISO): Elapsed Time.
`DIR`
  `dirent.h` (POSIX.1): Opening a Directory.
`int dirfd (DIR *`dirstream`)`
  `dirent.h` (GNU): Opening a Directory.
`char * dirname (char *`path`)`
  `libgen.h` (XPG): Finding Tokens in a String.
`div_t div (int` numerator`, int` denominator`)`
  `stdlib.h` (ISO): Integer Division.
`div_t`
  `stdlib.h` (ISO): Integer Division.
`char * dngettext (const char *`domain`, const char *`msgid1`, const char *`msgid2`, unsigned long int` n`)`
  `libintl.h` (GNU): Advanced gettext functions.
`double drand48 (void)`
  `stdlib.h` (SVID): SVID Random.
`int drand48_r (struct drand48_data *`buffer`, double *`result`)`
  `stdlib.h` (GNU): SVID Random.
`double drem (double` numerator`, double` denominator`)`
  `math.h` (BSD): Remainder Functions.
`float dremf (float` numerator`, float` denominator`)`
  `math.h` (BSD): Remainder Functions.
`long double dreml (long double` numerator`, long double` denominator`)`
  `math.h` (BSD): Remainder Functions.
`mode_t DTTOIF (int` dtype`)`
  `dirent.h` (BSD): Directory Entries.
`int dup (int` old`)`
  `unistd.h` (POSIX.1): Duplicating Descriptors.
`int dup2 (int` old`, int` new`)`
  `unistd.h` (POSIX.1): Duplicating Descriptors.
`int E2BIG`
  `errno.h` (POSIX.1: Argument list too long): Error Codes.
`int EACCES`
  `errno.h` (POSIX.1: Permission denied): Error Codes.
`int EADDRINUSE`
  `errno.h` (BSD: Address already in use): Error Codes.
`int EADDRNOTAVAIL`
  `errno.h` (BSD: Cannot assign requested address): Error Codes.
`int EADV`
  `errno.h` (Linux???: Advertise error): Error Codes.
`int EAFNOSUPPORT`
  `errno.h` (BSD: Address family not supported by protocol): Error Codes.
`int EAGAIN`
  `errno.h` (POSIX.1: Resource temporarily unavailable): Error Codes.
`int EALREADY`
  `errno.h` (BSD: Operation already in progress): Error Codes.
`int EAUTH`
  `errno.h` (BSD: Authentication error): Error Codes.
`int EBACKGROUND`
  `errno.h` (GNU: Inappropriate operation for background process): Error Codes.
`int EBADE`
  `errno.h` (Linux???: Invalid exchange): Error Codes.
`int EBADF`
  `errno.h` (POSIX.1: Bad file descriptor): Error Codes.
`int EBADFD`
  `errno.h` (Linux???: File descriptor in bad state): Error Codes.
`int EBADMSG`
  `errno.h` (XOPEN: Bad message): Error Codes.
`int EBADR`
  `errno.h` (Linux???: Invalid request descriptor): Error Codes.
`int EBADRPC`
  `errno.h` (BSD: RPC struct is bad): Error Codes.
`int EBADRQC`
  `errno.h` (Linux???: Invalid request code): Error Codes.
`int EBADSLT`
  `errno.h` (Linux???: Invalid slot): Error Codes.
`int EBFONT`
  `errno.h` (Linux???: Bad font file format): Error Codes.
`int EBUSY`
  `errno.h` (POSIX.1: Device or resource busy): Error Codes.
`int ECANCELED`
  `errno.h` (POSIX.1: Operation canceled): Error Codes.
`int ecb_crypt (char *`key`, char *`blocks`, unsigned` len`, unsigned` mode`)`
  `rpc/des_crypt.h` (SUNRPC): DES Encryption.
`int ECHILD`
  `errno.h` (POSIX.1: No child processes): Error Codes.
`tcflag_t ECHO`
  `termios.h` (POSIX.1): Local Modes.
`tcflag_t ECHOCTL`
  `termios.h` (BSD): Local Modes.
`tcflag_t ECHOE`
  `termios.h` (POSIX.1): Local Modes.
`tcflag_t ECHOK`
  `termios.h` (POSIX.1): Local Modes.
`tcflag_t ECHOKE`
  `termios.h` (BSD): Local Modes.
`tcflag_t ECHONL`
  `termios.h` (POSIX.1): Local Modes.
`tcflag_t ECHOPRT`
  `termios.h` (BSD): Local Modes.
`int ECHRNG`
  `errno.h` (Linux???: Channel number out of range): Error Codes.
`int ECOMM`
  `errno.h` (Linux???: Communication error on send): Error Codes.
`int ECONNABORTED`
  `errno.h` (BSD: Software caused connection abort): Error Codes.
`int ECONNREFUSED`
  `errno.h` (BSD: Connection refused): Error Codes.
`int ECONNRESET`
  `errno.h` (BSD: Connection reset by peer): Error Codes.
`char * ecvt (double` value`, int` ndigit`, int *`decpt`, int *`neg`)`
  `stdlib.h` (SVID, Unix98): System V Number Conversion.
`int ecvt_r (double` value`, int` ndigit`, int *`decpt`, int *`neg`, char *`buf`, size_t` len`)`
  `stdlib.h` (GNU): System V Number Conversion.
`int ED`
  `errno.h` (GNU: ?): Error Codes.
`int EDEADLK`
  `errno.h` (POSIX.1: Resource deadlock avoided): Error Codes.
`int EDEADLOCK`
  `errno.h` (Linux???: File locking deadlock error): Error Codes.
`int EDESTADDRREQ`
  `errno.h` (BSD: Destination address required): Error Codes.
`int EDIED`
  `errno.h` (GNU: Translator died): Error Codes.
`int EDOM`
  `errno.h` (ISO: Numerical argument out of domain): Error Codes.
`int EDOTDOT`
  `errno.h` (Linux???: RFS specific error): Error Codes.
`int EDQUOT`
  `errno.h` (BSD: Disk quota exceeded): Error Codes.
`int EEXIST`
  `errno.h` (POSIX.1: File exists): Error Codes.
`int EFAULT`
  `errno.h` (POSIX.1: Bad address): Error Codes.
`int EFBIG`
  `errno.h` (POSIX.1: File too large): Error Codes.
`int EFTYPE`
  `errno.h` (BSD: Inappropriate file type or format): Error Codes.
`int EGRATUITOUS`
  `errno.h` (GNU: Gratuitous error): Error Codes.
`int EGREGIOUS`
  `errno.h` (GNU: You really blew it this time): Error Codes.
`int EHOSTDOWN`
  `errno.h` (BSD: Host is down): Error Codes.
`int EHOSTUNREACH`
  `errno.h` (BSD: No route to host): Error Codes.
`int EHWPOISON`
  `errno.h` (Linux: Memory page has hardware error): Error Codes.
`int EIDRM`
  `errno.h` (XOPEN: Identifier removed): Error Codes.
`int EIEIO`
  `errno.h` (GNU: Computer bought the farm): Error Codes.
`int EILSEQ`
  `errno.h` (ISO: Invalid or incomplete multibyte or wide character): Error Codes.
`int EINPROGRESS`
  `errno.h` (BSD: Operation now in progress): Error Codes.
`int EINTR`
  `errno.h` (POSIX.1: Interrupted system call): Error Codes.
`int EINVAL`
  `errno.h` (POSIX.1: Invalid argument): Error Codes.
`int EIO`
  `errno.h` (POSIX.1: Input/output error): Error Codes.
`int EISCONN`
  `errno.h` (BSD: Transport endpoint is already connected): Error Codes.
`int EISDIR`
  `errno.h` (POSIX.1: Is a directory): Error Codes.
`int EISNAM`
  `errno.h` (Linux???: Is a named type file): Error Codes.
`int EKEYEXPIRED`
  `errno.h` (Linux: Key has expired): Error Codes.
`int EKEYREJECTED`
  `errno.h` (Linux: Key was rejected by service): Error Codes.
`int EKEYREVOKED`
  `errno.h` (Linux: Key has been revoked): Error Codes.
`int EL2HLT`
  `errno.h` (Obsolete: Level 2 halted): Error Codes.
`int EL2NSYNC`
  `errno.h` (Obsolete: Level 2 not synchronized): Error Codes.
`int EL3HLT`
  `errno.h` (Obsolete: Level 3 halted): Error Codes.
`int EL3RST`
  `errno.h` (Obsolete: Level 3 reset): Error Codes.
`int ELIBACC`
  `errno.h` (Linux???: Can not access a needed shared library): Error Codes.
`int ELIBBAD`
  `errno.h` (Linux???: Accessing a corrupted shared library): Error Codes.
`int ELIBEXEC`
  `errno.h` (Linux???: Cannot exec a shared library directly): Error Codes.
`int ELIBMAX`
  `errno.h` (Linux???: Attempting to link in too many shared libraries): Error Codes.
`int ELIBSCN`
  `errno.h` (Linux???: .lib section in a.out corrupted): Error Codes.
`int ELNRNG`
  `errno.h` (Linux???: Link number out of range): Error Codes.
`int ELOOP`
  `errno.h` (BSD: Too many levels of symbolic links): Error Codes.
`int EMEDIUMTYPE`
  `errno.h` (Linux???: Wrong medium type): Error Codes.
`int EMFILE`
  `errno.h` (POSIX.1: Too many open files): Error Codes.
`int EMLINK`
  `errno.h` (POSIX.1: Too many links): Error Codes.
`EMPTY`
  `utmp.h` (SVID): Manipulating the Database.
`EMPTY`
  `utmpx.h` (XPG4.2): XPG Functions.
`int EMSGSIZE`
  `errno.h` (BSD: Message too long): Error Codes.
`int EMULTIHOP`
  `errno.h` (XOPEN: Multihop attempted): Error Codes.
`int ENAMETOOLONG`
  `errno.h` (POSIX.1: File name too long): Error Codes.
`int ENAVAIL`
  `errno.h` (Linux???: No XENIX semaphores available): Error Codes.
`void encrypt (char *`block`, int` edflag`)`
  `crypt.h` (BSD, SVID): DES Encryption.
`void encrypt_r (char *`block`, int` edflag`, struct crypt_data *` data`)`
  `crypt.h` (GNU): DES Encryption.
`void endfsent (void)`
  `fstab.h` (BSD): fstab.
`void endgrent (void)`
  `grp.h` (SVID, BSD): Scanning All Groups.
`void endhostent (void)`
  `netdb.h` (BSD): Host Names.
`int endmntent (FILE *`stream`)`
  `mntent.h` (BSD): mtab.
`void endnetent (void)`
  `netdb.h` (BSD): Networks Database.
`void endnetgrent (void)`
  `netdb.h` (BSD): Lookup Netgroup.
`void endprotoent (void)`
  `netdb.h` (BSD): Protocols Database.
`void endpwent (void)`
  `pwd.h` (SVID, BSD): Scanning All Users.
`void endservent (void)`
  `netdb.h` (BSD): Services Database.
`void endutent (void)`
  `utmp.h` (SVID): Manipulating the Database.
`void endutxent (void)`
  `utmpx.h` (XPG4.2): XPG Functions.
`int ENEEDAUTH`
  `errno.h` (BSD: Need authenticator): Error Codes.
`int ENETDOWN`
  `errno.h` (BSD: Network is down): Error Codes.
`int ENETRESET`
  `errno.h` (BSD: Network dropped connection on reset): Error Codes.
`int ENETUNREACH`
  `errno.h` (BSD: Network is unreachable): Error Codes.
`int ENFILE`
  `errno.h` (POSIX.1: Too many open files in system): Error Codes.
`int ENOANO`
  `errno.h` (Linux???: No anode): Error Codes.
`int ENOBUFS`
  `errno.h` (BSD: No buffer space available): Error Codes.
`int ENOCSI`
  `errno.h` (Linux???: No CSI structure available): Error Codes.
`int ENODATA`
  `errno.h` (XOPEN: No data available): Error Codes.
`int ENODEV`
  `errno.h` (POSIX.1: No such device): Error Codes.
`int ENOENT`
  `errno.h` (POSIX.1: No such file or directory): Error Codes.
`int ENOEXEC`
  `errno.h` (POSIX.1: Exec format error): Error Codes.
`int ENOKEY`
  `errno.h` (Linux: Required key not available): Error Codes.
`int ENOLCK`
  `errno.h` (POSIX.1: No locks available): Error Codes.
`int ENOLINK`
  `errno.h` (XOPEN: Link has been severed): Error Codes.
`int ENOMEDIUM`
  `errno.h` (Linux???: No medium found): Error Codes.
`int ENOMEM`
  `errno.h` (POSIX.1: Cannot allocate memory): Error Codes.
`int ENOMSG`
  `errno.h` (XOPEN: No message of desired type): Error Codes.
`int ENONET`
  `errno.h` (Linux???: Machine is not on the network): Error Codes.
`int ENOPKG`
  `errno.h` (Linux???: Package not installed): Error Codes.
`int ENOPROTOOPT`
  `errno.h` (BSD: Protocol not available): Error Codes.
`int ENOSPC`
  `errno.h` (POSIX.1: No space left on device): Error Codes.
`int ENOSR`
  `errno.h` (XOPEN: Out of streams resources): Error Codes.
`int ENOSTR`
  `errno.h` (XOPEN: Device not a stream): Error Codes.
`int ENOSYS`
  `errno.h` (POSIX.1: Function not implemented): Error Codes.
`int ENOTBLK`
  `errno.h` (BSD: Block device required): Error Codes.
`int ENOTCONN`
  `errno.h` (BSD: Transport endpoint is not connected): Error Codes.
`int ENOTDIR`
  `errno.h` (POSIX.1: Not a directory): Error Codes.
`int ENOTEMPTY`
  `errno.h` (POSIX.1: Directory not empty): Error Codes.
`int ENOTNAM`
  `errno.h` (Linux???: Not a XENIX named type file): Error Codes.
`int ENOTRECOVERABLE`
  `errno.h` (Linux: State not recoverable): Error Codes.
`int ENOTSOCK`
  `errno.h` (BSD: Socket operation on non-socket): Error Codes.
`int ENOTSUP`
  `errno.h` (POSIX.1: Not supported): Error Codes.
`int ENOTTY`
  `errno.h` (POSIX.1: Inappropriate ioctl for device): Error Codes.
`int ENOTUNIQ`
  `errno.h` (Linux???: Name not unique on network): Error Codes.
`char ** environ`
  `unistd.h` (POSIX.1): Environment Access.
`error_t envz_add (char **`envz`, size_t *`envz_len`, const char *`name`, const char *`value`)`
  `envz.h` (GNU): Envz Functions.
`char * envz_entry (const char *`envz`, size_t` envz_len`, const char *`name`)`
  `envz.h` (GNU): Envz Functions.
`char * envz_get (const char *`envz`, size_t` envz_len`, const char *`name`)`
  `envz.h` (GNU): Envz Functions.
`error_t envz_merge (char **`envz`, size_t *`envz_len`, const char *`envz2`, size_t` envz2_len`, int` override`)`
  `envz.h` (GNU): Envz Functions.
`void envz_strip (char **`envz`, size_t *`envz_len`)`
  `envz.h` (GNU): Envz Functions.
`int ENXIO`
  `errno.h` (POSIX.1: No such device or address): Error Codes.
`int EOF`
  `stdio.h` (ISO): EOF and Errors.
`int EOPNOTSUPP`
  `errno.h` (BSD: Operation not supported): Error Codes.
`int EOVERFLOW`
  `errno.h` (XOPEN: Value too large for defined data type): Error Codes.
`int EOWNERDEAD`
  `errno.h` (Linux: Owner died): Error Codes.
`int EPERM`
  `errno.h` (POSIX.1: Operation not permitted): Error Codes.
`int EPFNOSUPPORT`
  `errno.h` (BSD: Protocol family not supported): Error Codes.
`int EPIPE`
  `errno.h` (POSIX.1: Broken pipe): Error Codes.
`int EPROCLIM`
  `errno.h` (BSD: Too many processes): Error Codes.
`int EPROCUNAVAIL`
  `errno.h` (BSD: RPC bad procedure for program): Error Codes.
`int EPROGMISMATCH`
  `errno.h` (BSD: RPC program version wrong): Error Codes.
`int EPROGUNAVAIL`
  `errno.h` (BSD: RPC program not available): Error Codes.
`int EPROTO`
  `errno.h` (XOPEN: Protocol error): Error Codes.
`int EPROTONOSUPPORT`
  `errno.h` (BSD: Protocol not supported): Error Codes.
`int EPROTOTYPE`
  `errno.h` (BSD: Protocol wrong type for socket): Error Codes.
`int EQUIV_CLASS_MAX`
  `limits.h` (POSIX.2): Utility Limits.
`double erand48 (unsigned short int` xsubi`[3])`
  `stdlib.h` (SVID): SVID Random.
`int erand48_r (unsigned short int` xsubi`[3], struct drand48_data *`buffer`, double *`result`)`
  `stdlib.h` (GNU): SVID Random.
`int ERANGE`
  `errno.h` (ISO: Numerical result out of range): Error Codes.
`int EREMCHG`
  `errno.h` (Linux???: Remote address changed): Error Codes.
`int EREMOTE`
  `errno.h` (BSD: Object is remote): Error Codes.
`int EREMOTEIO`
  `errno.h` (Linux???: Remote I/O error): Error Codes.
`int ERESTART`
  `errno.h` (Linux???: Interrupted system call should be restarted): Error Codes.
`double erf (double` x`)`
  `math.h` (SVID): Special Functions.
`double erfc (double` x`)`
  `math.h` (SVID): Special Functions.
`float erfcf (float` x`)`
  `math.h` (SVID): Special Functions.
`long double erfcl (long double` x`)`
  `math.h` (SVID): Special Functions.
`float erff (float` x`)`
  `math.h` (SVID): Special Functions.
`int ERFKILL`
  `errno.h` (Linux: Operation not possible due to RF-kill): Error Codes.
`long double erfl (long double` x`)`
  `math.h` (SVID): Special Functions.
`int EROFS`
  `errno.h` (POSIX.1: Read-only file system): Error Codes.
`int ERPCMISMATCH`
  `errno.h` (BSD: RPC version wrong): Error Codes.
`void err (int` status`, const char *`format`, ...)`
  `err.h` (BSD): Error Messages.
`volatile int errno`
  `errno.h` (ISO): Checking for Errors.
`void error (int` status`, int` errnum`, const char *`format`, ...)`
  `error.h` (GNU): Error Messages.
`void error_at_line (int` status`, int` errnum`, const char *`fname`, unsigned int` lineno`, const char *`format`, ...)`
  `error.h` (GNU): Error Messages.
`unsigned int error_message_count`
  `error.h` (GNU): Error Messages.
`int error_one_per_line`
  `error.h` (GNU): Error Messages.
`void errx (int` status`, const char *`format`, ...)`
  `err.h` (BSD): Error Messages.
`int ESHUTDOWN`
  `errno.h` (BSD: Cannot send after transport endpoint shutdown): Error Codes.
`int ESOCKTNOSUPPORT`
  `errno.h` (BSD: Socket type not supported): Error Codes.
`int ESPIPE`
  `errno.h` (POSIX.1: Illegal seek): Error Codes.
`int ESRCH`
  `errno.h` (POSIX.1: No such process): Error Codes.
`int ESRMNT`
  `errno.h` (Linux???: Srmount error): Error Codes.
`int ESTALE`
  `errno.h` (BSD: Stale file handle): Error Codes.
`int ESTRPIPE`
  `errno.h` (Linux???: Streams pipe error): Error Codes.
`int ETIME`
  `errno.h` (XOPEN: Timer expired): Error Codes.
`int ETIMEDOUT`
  `errno.h` (BSD: Connection timed out): Error Codes.
`int ETOOMANYREFS`
  `errno.h` (BSD: Too many references: cannot splice): Error Codes.
`int ETXTBSY`
  `errno.h` (BSD: Text file busy): Error Codes.
`int EUCLEAN`
  `errno.h` (Linux???: Structure needs cleaning): Error Codes.
`int EUNATCH`
  `errno.h` (Linux???: Protocol driver not attached): Error Codes.
`int EUSERS`
  `errno.h` (BSD: Too many users): Error Codes.
`int EWOULDBLOCK`
  `errno.h` (BSD: Operation would block): Error Codes.
`int EXDEV`
  `errno.h` (POSIX.1: Invalid cross-device link): Error Codes.
`int execl (const char *`filename`, const char *`arg0`, ...)`
  `unistd.h` (POSIX.1): Executing a File.
`int execle (const char *`filename`, const char *`arg0`, ..., char *const` env`[]``)`
  `unistd.h` (POSIX.1): Executing a File.
`int execlp (const char *`filename`, const char *`arg0`, ...)`
  `unistd.h` (POSIX.1): Executing a File.
`int execv (const char *`filename`, char *const` argv`[]``)`
  `unistd.h` (POSIX.1): Executing a File.
`int execve (const char *`filename`, char *const` argv`[]``, char *const` env`[]``)`
  `unistd.h` (POSIX.1): Executing a File.
`int execvp (const char *`filename`, char *const` argv`[]``)`
  `unistd.h` (POSIX.1): Executing a File.
`int EXFULL`
  `errno.h` (Linux???: Exchange full): Error Codes.
`void _Exit (int` status`)`
  `stdlib.h` (ISO): Termination Internals.
`void _exit (int` status`)`
  `unistd.h` (POSIX.1): Termination Internals.
`void exit (int` status`)`
  `stdlib.h` (ISO): Normal Termination.
`int EXIT_FAILURE`
  `stdlib.h` (ISO): Exit Status.
`int EXIT_SUCCESS`
  `stdlib.h` (ISO): Exit Status.
`double exp (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`double exp10 (double` x`)`
  `math.h` (GNU): Exponents and Logarithms.
`float exp10f (float` x`)`
  `math.h` (GNU): Exponents and Logarithms.
`long double exp10l (long double` x`)`
  `math.h` (GNU): Exponents and Logarithms.
`double exp2 (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float exp2f (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double exp2l (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float expf (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double expl (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`double expm1 (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float expm1f (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double expm1l (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`int EXPR_NEST_MAX`
  `limits.h` (POSIX.2): Utility Limits.
`double fabs (double` number`)`
  `math.h` (ISO): Absolute Value.
`float fabsf (float` number`)`
  `math.h` (ISO): Absolute Value.
`long double fabsl (long double` number`)`
  `math.h` (ISO): Absolute Value.
`size_t __fbufsize (FILE *`stream`)`
  `stdio_ext.h` (GNU): Controlling Buffering.
`int fchdir (int` filedes`)`
  `unistd.h` (XPG): Working Directory.
`int fchmod (int` filedes`, mode_t` mode`)`
  `sys/stat.h` (BSD): Setting Permissions.
`int fchown (int` filedes`, uid_t` owner`, gid_t` group`)`
  `unistd.h` (BSD): File Owner.
`int fclose (FILE *`stream`)`
  `stdio.h` (ISO): Closing Streams.
`int fcloseall (void)`
  `stdio.h` (GNU): Closing Streams.
`int fcntl (int` filedes`, int` command`, ...)`
  `fcntl.h` (POSIX.1): Control Operations.
`char * fcvt (double` value`, int` ndigit`, int *`decpt`, int *`neg`)`
  `stdlib.h` (SVID, Unix98): System V Number Conversion.
`int fcvt_r (double` value`, int` ndigit`, int *`decpt`, int *`neg`, char *`buf`, size_t` len`)`
  `stdlib.h` (SVID, Unix98): System V Number Conversion.
`int fdatasync (int` fildes`)`
  `unistd.h` (POSIX): Synchronizing I/O.
`int FD_CLOEXEC`
  `fcntl.h` (POSIX.1): Descriptor Flags.
`void FD_CLR (int` filedes`, fd_set *`set`)`
  `sys/types.h` (BSD): Waiting for I/O.
`double fdim (double` x`, double` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`float fdimf (float` x`, float` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`long double fdiml (long double` x`, long double` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`int FD_ISSET (int` filedes`, const fd_set *`set`)`
  `sys/types.h` (BSD): Waiting for I/O.
`FILE * fdopen (int` filedes`, const char *`opentype`)`
  `stdio.h` (POSIX.1): Descriptors and Streams.
`DIR * fdopendir (int` fd`)`
  `dirent.h` (GNU): Opening a Directory.
`void FD_SET (int` filedes`, fd_set *`set`)`
  `sys/types.h` (BSD): Waiting for I/O.
`fd_set`
  `sys/types.h` (BSD): Waiting for I/O.
`int FD_SETSIZE`
  `sys/types.h` (BSD): Waiting for I/O.
`int F_DUPFD`
  `fcntl.h` (POSIX.1): Duplicating Descriptors.
`void FD_ZERO (fd_set *`set`)`
  `sys/types.h` (BSD): Waiting for I/O.
`int feclearexcept (int` excepts`)`
  `fenv.h` (ISO): Status bit operations.
`int fedisableexcept (int` excepts`)`
  `fenv.h` (GNU): Control Functions.
`FE_DIVBYZERO`
  `fenv.h` (ISO): Status bit operations.
`FE_DOWNWARD`
  `fenv.h` (ISO): Rounding.
`int feenableexcept (int` excepts`)`
  `fenv.h` (GNU): Control Functions.
`int fegetenv (fenv_t *`envp`)`
  `fenv.h` (ISO): Control Functions.
`int fegetexcept (void)`
  `fenv.h` (GNU): Control Functions.
`int fegetexceptflag (fexcept_t *`flagp`, int` excepts`)`
  `fenv.h` (ISO): Status bit operations.
`int fegetround (void)`
  `fenv.h` (ISO): Rounding.
`int feholdexcept (fenv_t *`envp`)`
  `fenv.h` (ISO): Control Functions.
`FE_INEXACT`
  `fenv.h` (ISO): Status bit operations.
`FE_INVALID`
  `fenv.h` (ISO): Status bit operations.
`int feof (FILE *`stream`)`
  `stdio.h` (ISO): EOF and Errors.
`int feof_unlocked (FILE *`stream`)`
  `stdio.h` (GNU): EOF and Errors.
`FE_OVERFLOW`
  `fenv.h` (ISO): Status bit operations.
`int feraiseexcept (int` excepts`)`
  `fenv.h` (ISO): Status bit operations.
`int ferror (FILE *`stream`)`
  `stdio.h` (ISO): EOF and Errors.
`int ferror_unlocked (FILE *`stream`)`
  `stdio.h` (GNU): EOF and Errors.
`int fesetenv (const fenv_t *`envp`)`
  `fenv.h` (ISO): Control Functions.
`int fesetexceptflag (const fexcept_t *`flagp`, int` excepts`)`
  `fenv.h` (ISO): Status bit operations.
`int fesetround (int` round`)`
  `fenv.h` (ISO): Rounding.
`int fetestexcept (int` excepts`)`
  `fenv.h` (ISO): Status bit operations.
`FE_TONEAREST`
  `fenv.h` (ISO): Rounding.
`FE_TOWARDZERO`
  `fenv.h` (ISO): Rounding.
`FE_UNDERFLOW`
  `fenv.h` (ISO): Status bit operations.
`int feupdateenv (const fenv_t *`envp`)`
  `fenv.h` (ISO): Control Functions.
`FE_UPWARD`
  `fenv.h` (ISO): Rounding.
`int fflush (FILE *`stream`)`
  `stdio.h` (ISO): Flushing Buffers.
`int fflush_unlocked (FILE *`stream`)`
  `stdio.h` (POSIX): Flushing Buffers.
`int fgetc (FILE *`stream`)`
  `stdio.h` (ISO): Character Input.
`int fgetc_unlocked (FILE *`stream`)`
  `stdio.h` (POSIX): Character Input.
`int F_GETFD`
  `fcntl.h` (POSIX.1): Descriptor Flags.
`int F_GETFL`
  `fcntl.h` (POSIX.1): Getting File Status Flags.
`struct group * fgetgrent (FILE *`stream`)`
  `grp.h` (SVID): Scanning All Groups.
`int fgetgrent_r (FILE *`stream`, struct group *`result_buf`, char *`buffer`, size_t` buflen`, struct group **`result`)`
  `grp.h` (GNU): Scanning All Groups.
`int F_GETLK`
  `fcntl.h` (POSIX.1): File Locks.
`int F_GETOWN`
  `fcntl.h` (BSD): Interrupt Input.
`int fgetpos (FILE *`stream`, fpos_t *`position`)`
  `stdio.h` (ISO): Portable Positioning.
`int fgetpos64 (FILE *`stream`, fpos64_t *`position`)`
  `stdio.h` (Unix98): Portable Positioning.
`struct passwd * fgetpwent (FILE *`stream`)`
  `pwd.h` (SVID): Scanning All Users.
`int fgetpwent_r (FILE *`stream`, struct passwd *`result_buf`, char *`buffer`, size_t` buflen`, struct passwd **`result`)`
  `pwd.h` (GNU): Scanning All Users.
`char * fgets (char *`s`, int` count`, FILE *`stream`)`
  `stdio.h` (ISO): Line Input.
`char * fgets_unlocked (char *`s`, int` count`, FILE *`stream`)`
  `stdio.h` (GNU): Line Input.
`wint_t fgetwc (FILE *`stream`)`
  `wchar.h` (ISO): Character Input.
`wint_t fgetwc_unlocked (FILE *`stream`)`
  `wchar.h` (GNU): Character Input.
`wchar_t * fgetws (wchar_t *`ws`, int` count`, FILE *`stream`)`
  `wchar.h` (ISO): Line Input.
`wchar_t * fgetws_unlocked (wchar_t *`ws`, int` count`, FILE *`stream`)`
  `wchar.h` (GNU): Line Input.
`FILE`
  `stdio.h` (ISO): Streams.
`int FILENAME_MAX`
  `stdio.h` (ISO): Limits for Files.
`int fileno (FILE *`stream`)`
  `stdio.h` (POSIX.1): Descriptors and Streams.
`int fileno_unlocked (FILE *`stream`)`
  `stdio.h` (GNU): Descriptors and Streams.
`int finite (double` x`)`
  `math.h` (BSD): Floating Point Classes.
`int finitef (float` x`)`
  `math.h` (BSD): Floating Point Classes.
`int finitel (long double` x`)`
  `math.h` (BSD): Floating Point Classes.
`int __flbf (FILE *`stream`)`
  `stdio_ext.h` (GNU): Controlling Buffering.
`void flockfile (FILE *`stream`)`
  `stdio.h` (POSIX): Streams and Threads.
`double floor (double` x`)`
  `math.h` (ISO): Rounding Functions.
`float floorf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long double floorl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`FLT_DIG`
  `float.h` (ISO): Floating Point Parameters.
`FLT_EPSILON`
  `float.h` (ISO): Floating Point Parameters.
`FLT_MANT_DIG`
  `float.h` (ISO): Floating Point Parameters.
`FLT_MAX`
  `float.h` (ISO): Floating Point Parameters.
`FLT_MAX_10_EXP`
  `float.h` (ISO): Floating Point Parameters.
`FLT_MAX_EXP`
  `float.h` (ISO): Floating Point Parameters.
`FLT_MIN`
  `float.h` (ISO): Floating Point Parameters.
`FLT_MIN_10_EXP`
  `float.h` (ISO): Floating Point Parameters.
`FLT_MIN_EXP`
  `float.h` (ISO): Floating Point Parameters.
`FLT_RADIX`
  `float.h` (ISO): Floating Point Parameters.
`FLT_ROUNDS`
  `float.h` (ISO): Floating Point Parameters.
`void _flushlbf (void)`
  `stdio_ext.h` (GNU): Flushing Buffers.
`tcflag_t FLUSHO`
  `termios.h` (BSD): Local Modes.
`double fma (double` x`, double` y`, double` z`)`
  `math.h` (ISO): Misc FP Arithmetic.
`float fmaf (float` x`, float` y`, float` z`)`
  `math.h` (ISO): Misc FP Arithmetic.
`long double fmal (long double` x`, long double` y`, long double` z`)`
  `math.h` (ISO): Misc FP Arithmetic.
`double fmax (double` x`, double` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`float fmaxf (float` x`, float` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`long double fmaxl (long double` x`, long double` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`FILE * fmemopen (void *`buf`, size_t` size`, const char *`opentype`)`
  `stdio.h` (GNU): String Streams.
`double fmin (double` x`, double` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`float fminf (float` x`, float` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`long double fminl (long double` x`, long double` y`)`
  `math.h` (ISO): Misc FP Arithmetic.
`double fmod (double` numerator`, double` denominator`)`
  `math.h` (ISO): Remainder Functions.
`float fmodf (float` numerator`, float` denominator`)`
  `math.h` (ISO): Remainder Functions.
`long double fmodl (long double` numerator`, long double` denominator`)`
  `math.h` (ISO): Remainder Functions.
`int fmtmsg (long int` classification`, const char *`label`, int` severity`, const char *`text`, const char *`action`, const char *`tag`)`
  `fmtmsg.h` (XPG): Printing Formatted Messages.
`int fnmatch (const char *`pattern`, const char *`string`, int` flags`)`
  `fnmatch.h` (POSIX.2): Wildcard Matching.
`FNM_CASEFOLD`
  `fnmatch.h` (GNU): Wildcard Matching.
`FNM_EXTMATCH`
  `fnmatch.h` (GNU): Wildcard Matching.
`FNM_FILE_NAME`
  `fnmatch.h` (GNU): Wildcard Matching.
`FNM_LEADING_DIR`
  `fnmatch.h` (GNU): Wildcard Matching.
`FNM_NOESCAPE`
  `fnmatch.h` (POSIX.2): Wildcard Matching.
`FNM_PATHNAME`
  `fnmatch.h` (POSIX.2): Wildcard Matching.
`FNM_PERIOD`
  `fnmatch.h` (POSIX.2): Wildcard Matching.
`int F_OK`
  `unistd.h` (POSIX.1): Testing File Access.
`FILE * fopen (const char *`filename`, const char *`opentype`)`
  `stdio.h` (ISO): Opening Streams.
`FILE * fopen64 (const char *`filename`, const char *`opentype`)`
  `stdio.h` (Unix98): Opening Streams.
`FILE * fopencookie (void *`cookie`, const char *`opentype`, cookie_io_functions_t` io-functions`)`
  `stdio.h` (GNU): Streams and Cookies.
`int FOPEN_MAX`
  `stdio.h` (ISO): Opening Streams.
`pid_t fork (void)`
  `unistd.h` (POSIX.1): Creating a Process.
`int forkpty (int *`amaster`, char *`name`, const struct termios *`termp`, const struct winsize *`winp`)`
  `pty.h` (BSD): Pseudo-Terminal Pairs.
`long int fpathconf (int` filedes`, int` parameter`)`
  `unistd.h` (POSIX.1): Pathconf.
`int fpclassify (`float-type x`)`
  `math.h` (ISO): Floating Point Classes.
`FPE_DECOVF_TRAP`
  `signal.h` (BSD): Program Error Signals.
`FPE_FLTDIV_FAULT`
  `signal.h` (BSD): Program Error Signals.
`FPE_FLTDIV_TRAP`
  `signal.h` (BSD): Program Error Signals.
`FPE_FLTOVF_FAULT`
  `signal.h` (BSD): Program Error Signals.
`FPE_FLTOVF_TRAP`
  `signal.h` (BSD): Program Error Signals.
`FPE_FLTUND_FAULT`
  `signal.h` (BSD): Program Error Signals.
`FPE_FLTUND_TRAP`
  `signal.h` (BSD): Program Error Signals.
`FPE_INTDIV_TRAP`
  `signal.h` (BSD): Program Error Signals.
`FPE_INTOVF_TRAP`
  `signal.h` (BSD): Program Error Signals.
`size_t __fpending (FILE *`stream`)`
  `stdio_ext.h` (GNU): Controlling Buffering.
`FPE_SUBRNG_TRAP`
  `signal.h` (BSD): Program Error Signals.
`int FP_ILOGB0`
  `math.h` (ISO): Exponents and Logarithms.
`int FP_ILOGBNAN`
  `math.h` (ISO): Exponents and Logarithms.
`fpos64_t`
  `stdio.h` (Unix98): Portable Positioning.
`fpos_t`
  `stdio.h` (ISO): Portable Positioning.
`int fprintf (FILE *`stream`, const char *`template`, ...)`
  `stdio.h` (ISO): Formatted Output Functions.
`void __fpurge (FILE *`stream`)`
  `stdio_ext.h` (GNU): Flushing Buffers.
`int fputc (int` c`, FILE *`stream`)`
  `stdio.h` (ISO): Simple Output.
`int fputc_unlocked (int` c`, FILE *`stream`)`
  `stdio.h` (POSIX): Simple Output.
`int fputs (const char *`s`, FILE *`stream`)`
  `stdio.h` (ISO): Simple Output.
`int fputs_unlocked (const char *`s`, FILE *`stream`)`
  `stdio.h` (GNU): Simple Output.
`wint_t fputwc (wchar_t` wc`, FILE *`stream`)`
  `wchar.h` (ISO): Simple Output.
`wint_t fputwc_unlocked (wchar_t` wc`, FILE *`stream`)`
  `wchar.h` (POSIX): Simple Output.
`int fputws (const wchar_t *`ws`, FILE *`stream`)`
  `wchar.h` (ISO): Simple Output.
`int fputws_unlocked (const wchar_t *`ws`, FILE *`stream`)`
  `wchar.h` (GNU): Simple Output.
`F_RDLCK`
  `fcntl.h` (POSIX.1): File Locks.
`size_t fread (void *`data`, size_t` size`, size_t` count`, FILE *`stream`)`
  `stdio.h` (ISO): Block Input/Output.
`int __freadable (FILE *`stream`)`
  `stdio_ext.h` (GNU): Opening Streams.
`int __freading (FILE *`stream`)`
  `stdio_ext.h` (GNU): Opening Streams.
`size_t fread_unlocked (void *`data`, size_t` size`, size_t` count`, FILE *`stream`)`
  `stdio.h` (GNU): Block Input/Output.
`void free (void *`ptr`)`
  `malloc.h`, `stdlib.h` (ISO): Freeing after Malloc.
`__free_hook`
  `malloc.h` (GNU): Hooks for Malloc.
`FILE * freopen (const char *`filename`, const char *`opentype`, FILE *`stream`)`
  `stdio.h` (ISO): Opening Streams.
`FILE * freopen64 (const char *`filename`, const char *`opentype`, FILE *`stream`)`
  `stdio.h` (Unix98): Opening Streams.
`double frexp (double` value`, int *`exponent`)`
  `math.h` (ISO): Normalization Functions.
`float frexpf (float` value`, int *`exponent`)`
  `math.h` (ISO): Normalization Functions.
`long double frexpl (long double` value`, int *`exponent`)`
  `math.h` (ISO): Normalization Functions.
`int fscanf (FILE *`stream`, const char *`template`, ...)`
  `stdio.h` (ISO): Formatted Input Functions.
`int fseek (FILE *`stream`, long int` offset`, int` whence`)`
  `stdio.h` (ISO): File Positioning.
`int fseeko (FILE *`stream`, off_t` offset`, int` whence`)`
  `stdio.h` (Unix98): File Positioning.
`int fseeko64 (FILE *`stream`, off64_t` offset`, int` whence`)`
  `stdio.h` (Unix98): File Positioning.
`int F_SETFD`
  `fcntl.h` (POSIX.1): Descriptor Flags.
`int F_SETFL`
  `fcntl.h` (POSIX.1): Getting File Status Flags.
`int F_SETLK`
  `fcntl.h` (POSIX.1): File Locks.
`int F_SETLKW`
  `fcntl.h` (POSIX.1): File Locks.
`int __fsetlocking (FILE *`stream`, int` type`)`
  `stdio_ext.h` (GNU): Streams and Threads.
`int F_SETOWN`
  `fcntl.h` (BSD): Interrupt Input.
`int fsetpos (FILE *`stream`, const fpos_t *`position`)`
  `stdio.h` (ISO): Portable Positioning.
`int fsetpos64 (FILE *`stream`, const fpos64_t *`position`)`
  `stdio.h` (Unix98): Portable Positioning.
`int fstat (int` filedes`, struct stat *`buf`)`
  `sys/stat.h` (POSIX.1): Reading Attributes.
`int fstat64 (int` filedes`, struct stat64 *`buf`)`
  `sys/stat.h` (Unix98): Reading Attributes.
`int fsync (int` fildes`)`
  `unistd.h` (POSIX): Synchronizing I/O.
`long int ftell (FILE *`stream`)`
  `stdio.h` (ISO): File Positioning.
`off_t ftello (FILE *`stream`)`
  `stdio.h` (Unix98): File Positioning.
`off64_t ftello64 (FILE *`stream`)`
  `stdio.h` (Unix98): File Positioning.
`int ftruncate (int` fd`, off_t` length`)`
  `unistd.h` (POSIX): File Size.
`int ftruncate64 (int` id`, off64_t` length`)`
  `unistd.h` (Unix98): File Size.
`int ftrylockfile (FILE *`stream`)`
  `stdio.h` (POSIX): Streams and Threads.
`int ftw (const char *`filename`, __ftw_func_t` func`, int` descriptors`)`
  `ftw.h` (SVID): Working with Directory Trees.
`int ftw64 (const char *`filename`, __ftw64_func_t` func`, int` descriptors`)`
  `ftw.h` (Unix98): Working with Directory Trees.
`__ftw64_func_t`
  `ftw.h` (GNU): Working with Directory Trees.
`__ftw_func_t`
  `ftw.h` (GNU): Working with Directory Trees.
`F_UNLCK`
  `fcntl.h` (POSIX.1): File Locks.
`void funlockfile (FILE *`stream`)`
  `stdio.h` (POSIX): Streams and Threads.
`int futimes (int` fd`, const struct timeval` tvp`[2]``)`
  `sys/time.h` (BSD): File Times.
`int fwide (FILE *`stream`, int` mode`)`
  `wchar.h` (ISO): Streams and I18N.
`int fwprintf (FILE *`stream`, const wchar_t *`template`, ...)`
  `wchar.h` (ISO): Formatted Output Functions.
`int __fwritable (FILE *`stream`)`
  `stdio_ext.h` (GNU): Opening Streams.
`size_t fwrite (const void *`data`, size_t` size`, size_t` count`, FILE *`stream`)`
  `stdio.h` (ISO): Block Input/Output.
`size_t fwrite_unlocked (const void *`data`, size_t` size`, size_t` count`, FILE *`stream`)`
  `stdio.h` (GNU): Block Input/Output.
`int __fwriting (FILE *`stream`)`
  `stdio_ext.h` (GNU): Opening Streams.
`F_WRLCK`
  `fcntl.h` (POSIX.1): File Locks.
`int fwscanf (FILE *`stream`, const wchar_t *`template`, ...)`
  `wchar.h` (ISO): Formatted Input Functions.
`double gamma (double` x`)`
  `math.h` (SVID): Special Functions.
`float gammaf (float` x`)`
  `math.h` (SVID): Special Functions.
`long double gammal (long double` x`)`
  `math.h` (SVID): Special Functions.
`void (*__gconv_end_fct) (struct gconv_step *)`
  `gconv.h` (GNU): glibc iconv Implementation.
`int (*__gconv_fct) (struct __gconv_step *, struct __gconv_step_data *, const char **, const char *, size_t *, int)`
  `gconv.h` (GNU): glibc iconv Implementation.
`int (*__gconv_init_fct) (struct __gconv_step *)`
  `gconv.h` (GNU): glibc iconv Implementation.
`char * gcvt (double` value`, int` ndigit`, char *`buf`)`
  `stdlib.h` (SVID, Unix98): System V Number Conversion.
`unsigned long int getauxval (unsigned long int` type`)`
  `sys/auxv.h` (sys/auxv.h): Auxiliary Vector.
`long int get_avphys_pages (void)`
  `sys/sysinfo.h` (GNU): Query Memory Parameters.
`int getc (FILE *`stream`)`
  `stdio.h` (ISO): Character Input.
`int getchar (void)`
  `stdio.h` (ISO): Character Input.
`int getchar_unlocked (void)`
  `stdio.h` (POSIX): Character Input.
`int getcontext (ucontext_t *`ucp`)`
  `ucontext.h` (SVID): System V contexts.
`int getc_unlocked (FILE *`stream`)`
  `stdio.h` (POSIX): Character Input.
`char * get_current_dir_name (void)`
  `unistd.h` (GNU): Working Directory.
`char * getcwd (char *`buffer`, size_t` size`)`
  `unistd.h` (POSIX.1): Working Directory.
`struct tm * getdate (const char *`string`)`
  `time.h` (Unix98): General Time String Parsing.
`getdate_err`
  `time.h` (Unix98): General Time String Parsing.
`int getdate_r (const char *`string`, struct tm *`tp`)`
  `time.h` (GNU): General Time String Parsing.
`ssize_t getdelim (char **`lineptr`, size_t *`n`, int` delimiter`, FILE *`stream`)`
  `stdio.h` (GNU): Line Input.
`int getdomainnname (char *`name`, size_t` length`)`
  `unistd.h` (???): Host Identification.
`gid_t getegid (void)`
  `unistd.h` (POSIX.1): Reading Persona.
`char * getenv (const char *`name`)`
  `stdlib.h` (ISO): Environment Access.
`uid_t geteuid (void)`
  `unistd.h` (POSIX.1): Reading Persona.
`struct fstab * getfsent (void)`
  `fstab.h` (BSD): fstab.
`struct fstab * getfsfile (const char *`name`)`
  `fstab.h` (BSD): fstab.
`struct fstab * getfsspec (const char *`name`)`
  `fstab.h` (BSD): fstab.
`gid_t getgid (void)`
  `unistd.h` (POSIX.1): Reading Persona.
`struct group * getgrent (void)`
  `grp.h` (SVID, BSD): Scanning All Groups.
`int getgrent_r (struct group *`result_buf`, char *`buffer`, size_t` buflen`, struct group **`result`)`
  `grp.h` (GNU): Scanning All Groups.
`struct group * getgrgid (gid_t` gid`)`
  `grp.h` (POSIX.1): Lookup Group.
`int getgrgid_r (gid_t` gid`, struct group *`result_buf`, char *`buffer`, size_t` buflen`, struct group **`result`)`
  `grp.h` (POSIX.1c): Lookup Group.
`struct group * getgrnam (const char *`name`)`
  `grp.h` (SVID, BSD): Lookup Group.
`int getgrnam_r (const char *`name`, struct group *`result_buf`, char *`buffer`, size_t` buflen`, struct group **`result`)`
  `grp.h` (POSIX.1c): Lookup Group.
`int getgrouplist (const char *`user`, gid_t` group`, gid_t *`groups`, int *`ngroups`)`
  `grp.h` (BSD): Setting Groups.
`int getgroups (int` count`, gid_t *`groups`)`
  `unistd.h` (POSIX.1): Reading Persona.
`struct hostent * gethostbyaddr (const void *`addr`, socklen_t` length`, int` format`)`
  `netdb.h` (BSD): Host Names.
`int gethostbyaddr_r (const void *`addr`, socklen_t` length`, int` format`, struct hostent *restrict` result_buf`, char *restrict` buf`, size_t` buflen`, struct hostent **restrict` result`, int *restrict` h_errnop`)`
  `netdb.h` (GNU): Host Names.
`struct hostent * gethostbyname (const char *`name`)`
  `netdb.h` (BSD): Host Names.
`struct hostent * gethostbyname2 (const char *`name`, int` af`)`
  `netdb.h` (IPv6 Basic API): Host Names.
`int gethostbyname2_r (const char *`name`, int` af`, struct hostent *restrict` result_buf`, char *restrict` buf`, size_t` buflen`, struct hostent **restrict` result`, int *restrict` h_errnop`)`
  `netdb.h` (GNU): Host Names.
`int gethostbyname_r (const char *restrict` name`, struct hostent *restrict` result_buf`, char *restrict` buf`, size_t` buflen`, struct hostent **restrict` result`, int *restrict` h_errnop`)`
  `netdb.h` (GNU): Host Names.
`struct hostent * gethostent (void)`
  `netdb.h` (BSD): Host Names.
`long int gethostid (void)`
  `unistd.h` (BSD): Host Identification.
`int gethostname (char *`name`, size_t` size`)`
  `unistd.h` (BSD): Host Identification.
`int getitimer (int` which`, struct itimerval *`old`)`
  `sys/time.h` (BSD): Setting an Alarm.
`ssize_t getline (char **`lineptr`, size_t *`n`, FILE *`stream`)`
  `stdio.h` (GNU): Line Input.
`int getloadavg (double` loadavg`[], int` nelem`)`
  `stdlib.h` (BSD): Processor Resources.
`char * getlogin (void)`
  `unistd.h` (POSIX.1): Who Logged In.
`struct mntent * getmntent (FILE *`stream`)`
  `mntent.h` (BSD): mtab.
`struct mntent * getmntent_r (FILE *`stream`, struct mntent *`result`, char *`buffer`, int` bufsize`)`
  `mntent.h` (BSD): mtab.
`struct netent * getnetbyaddr (uint32_t` net`, int` type`)`
  `netdb.h` (BSD): Networks Database.
`struct netent * getnetbyname (const char *`name`)`
  `netdb.h` (BSD): Networks Database.
`struct netent * getnetent (void)`
  `netdb.h` (BSD): Networks Database.
`int getnetgrent (char **`hostp`, char **`userp`, char **`domainp`)`
  `netdb.h` (BSD): Lookup Netgroup.
`int getnetgrent_r (char **`hostp`, char **`userp`, char **`domainp`, char *`buffer`, size_t` buflen`)`
  `netdb.h` (GNU): Lookup Netgroup.
`int get_nprocs (void)`
  `sys/sysinfo.h` (GNU): Processor Resources.
`int get_nprocs_conf (void)`
  `sys/sysinfo.h` (GNU): Processor Resources.
`int getopt (int` argc`, char *const *`argv`, const char *`options`)`
  `unistd.h` (POSIX.2): Using Getopt.
`int getopt_long (int` argc`, char *const *`argv`, const char *`shortopts`, const struct option *`longopts`, int *`indexptr`)`
  `getopt.h` (GNU): Getopt Long Options.
`int getopt_long_only (int` argc`, char *const *`argv`, const char *`shortopts`, const struct option *`longopts`, int *`indexptr`)`
  `getopt.h` (GNU): Getopt Long Options.
`int getpagesize (void)`
  `unistd.h` (BSD): Query Memory Parameters.
`char * getpass (const char *`prompt`)`
  `unistd.h` (BSD): getpass.
`int getpeername (int` socket`, struct sockaddr *`addr`, socklen_t *`length-ptr`)`
  `sys/socket.h` (BSD): Who is Connected.
`int getpgid (pid_t` pid`)`
  `unistd.h` (SVID): Process Group Functions.
`pid_t getpgrp (pid_t` pid`)`
  `unistd.h` (BSD): Process Group Functions.
`pid_t getpgrp (void)`
  `unistd.h` (POSIX.1): Process Group Functions.
`long int get_phys_pages (void)`
  `sys/sysinfo.h` (GNU): Query Memory Parameters.
`pid_t getpid (void)`
  `unistd.h` (POSIX.1): Process Identification.
`pid_t getppid (void)`
  `unistd.h` (POSIX.1): Process Identification.
`int getpriority (int` class`, int` id`)`
  `sys/resource.h` (BSD,POSIX): Traditional Scheduling Functions.
`struct protoent * getprotobyname (const char *`name`)`
  `netdb.h` (BSD): Protocols Database.
`struct protoent * getprotobynumber (int` protocol`)`
  `netdb.h` (BSD): Protocols Database.
`struct protoent * getprotoent (void)`
  `netdb.h` (BSD): Protocols Database.
`int getpt (void)`
  `stdlib.h` (GNU): Allocation.
`struct passwd * getpwent (void)`
  `pwd.h` (POSIX.1): Scanning All Users.
`int getpwent_r (struct passwd *`result_buf`, char *`buffer`, size_t` buflen`, struct passwd **`result`)`
  `pwd.h` (GNU): Scanning All Users.
`struct passwd * getpwnam (const char *`name`)`
  `pwd.h` (POSIX.1): Lookup User.
`int getpwnam_r (const char *`name`, struct passwd *`result_buf`, char *`buffer`, size_t` buflen`, struct passwd **`result`)`
  `pwd.h` (POSIX.1c): Lookup User.
`struct passwd * getpwuid (uid_t` uid`)`
  `pwd.h` (POSIX.1): Lookup User.
`int getpwuid_r (uid_t` uid`, struct passwd *`result_buf`, char *`buffer`, size_t` buflen`, struct passwd **`result`)`
  `pwd.h` (POSIX.1c): Lookup User.
`int getrlimit (int` resource`, struct rlimit *`rlp`)`
  `sys/resource.h` (BSD): Limits on Resources.
`int getrlimit64 (int` resource`, struct rlimit64 *`rlp`)`
  `sys/resource.h` (Unix98): Limits on Resources.
`int getrusage (int` processes`, struct rusage *`rusage`)`
  `sys/resource.h` (BSD): Resource Usage.
`char * gets (char *`s`)`
  `stdio.h` (ISO): Line Input.
`struct servent * getservbyname (const char *`name`, const char *`proto`)`
  `netdb.h` (BSD): Services Database.
`struct servent * getservbyport (int` port`, const char *`proto`)`
  `netdb.h` (BSD): Services Database.
`struct servent * getservent (void)`
  `netdb.h` (BSD): Services Database.
`pid_t getsid (pid_t` pid`)`
  `unistd.h` (SVID): Process Group Functions.
`int getsockname (int` socket`, struct sockaddr *`addr`, socklen_t *`length-ptr`)`
  `sys/socket.h` (BSD): Reading Address.
`int getsockopt (int` socket`, int` level`, int` optname`, void *`optval`, socklen_t *`optlen-ptr`)`
  `sys/socket.h` (BSD): Socket Option Functions.
`int getsubopt (char **`optionp`, char *const *`tokens`, char **`valuep`)`
  `stdlib.h` (stdlib.h): Suboptions Example.
`char * gettext (const char *`msgid`)`
  `libintl.h` (GNU): Translation with gettext.
`int gettimeofday (struct timeval *`tp`, struct timezone *`tzp`)`
  `sys/time.h` (BSD): High-Resolution Calendar.
`uid_t getuid (void)`
  `unistd.h` (POSIX.1): Reading Persona.
`mode_t getumask (void)`
  `sys/stat.h` (GNU): Setting Permissions.
`struct utmp * getutent (void)`
  `utmp.h` (SVID): Manipulating the Database.
`int getutent_r (struct utmp *`buffer`, struct utmp **`result`)`
  `utmp.h` (GNU): Manipulating the Database.
`struct utmp * getutid (const struct utmp *`id`)`
  `utmp.h` (SVID): Manipulating the Database.
`int getutid_r (const struct utmp *`id`, struct utmp *`buffer`, struct utmp **`result`)`
  `utmp.h` (GNU): Manipulating the Database.
`struct utmp * getutline (const struct utmp *`line`)`
  `utmp.h` (SVID): Manipulating the Database.
`int getutline_r (const struct utmp *`line`, struct utmp *`buffer`, struct utmp **`result`)`
  `utmp.h` (GNU): Manipulating the Database.
`int getutmp (const struct utmpx *`utmpx`, struct utmp *`utmp`)`
  `utmp.h` (GNU): XPG Functions.
`int getutmpx (const struct utmp *`utmp`, struct utmpx *`utmpx`)`
  `utmp.h` (GNU): XPG Functions.
`struct utmpx * getutxent (void)`
  `utmpx.h` (XPG4.2): XPG Functions.
`struct utmpx * getutxid (const struct utmpx *`id`)`
  `utmpx.h` (XPG4.2): XPG Functions.
`struct utmpx * getutxline (const struct utmpx *`line`)`
  `utmpx.h` (XPG4.2): XPG Functions.
`int getw (FILE *`stream`)`
  `stdio.h` (SVID): Character Input.
`wint_t getwc (FILE *`stream`)`
  `wchar.h` (ISO): Character Input.
`wint_t getwchar (void)`
  `wchar.h` (ISO): Character Input.
`wint_t getwchar_unlocked (void)`
  `wchar.h` (GNU): Character Input.
`wint_t getwc_unlocked (FILE *`stream`)`
  `wchar.h` (GNU): Character Input.
`char * getwd (char *`buffer`)`
  `unistd.h` (BSD): Working Directory.
`gid_t`
  `sys/types.h` (POSIX.1): Reading Persona.
`int glob (const char *`pattern`, int` flags`, int (*`errfunc`) (const char *`filename`, int` error-code`), glob_t *`vector-ptr`)`
  `glob.h` (POSIX.2): Calling Glob.
`int glob64 (const char *`pattern`, int` flags`, int (*`errfunc`) (const char *`filename`, int` error-code`), glob64_t *`vector-ptr`)`
  `glob.h` (GNU): Calling Glob.
`glob64_t`
  `glob.h` (GNU): Calling Glob.
`GLOB_ABORTED`
  `glob.h` (POSIX.2): Calling Glob.
`GLOB_ALTDIRFUNC`
  `glob.h` (GNU): More Flags for Globbing.
`GLOB_APPEND`
  `glob.h` (POSIX.2): Flags for Globbing.
`GLOB_BRACE`
  `glob.h` (GNU): More Flags for Globbing.
`GLOB_DOOFFS`
  `glob.h` (POSIX.2): Flags for Globbing.
`GLOB_ERR`
  `glob.h` (POSIX.2): Flags for Globbing.
`void globfree (glob_t *`pglob`)`
  `glob.h` (POSIX.2): More Flags for Globbing.
`void globfree64 (glob64_t *`pglob`)`
  `glob.h` (GNU): More Flags for Globbing.
`GLOB_MAGCHAR`
  `glob.h` (GNU): More Flags for Globbing.
`GLOB_MARK`
  `glob.h` (POSIX.2): Flags for Globbing.
`GLOB_NOCHECK`
  `glob.h` (POSIX.2): Flags for Globbing.
`GLOB_NOESCAPE`
  `glob.h` (POSIX.2): Flags for Globbing.
`GLOB_NOMAGIC`
  `glob.h` (GNU): More Flags for Globbing.
`GLOB_NOMATCH`
  `glob.h` (POSIX.2): Calling Glob.
`GLOB_NOSORT`
  `glob.h` (POSIX.2): Flags for Globbing.
`GLOB_NOSPACE`
  `glob.h` (POSIX.2): Calling Glob.
`GLOB_ONLYDIR`
  `glob.h` (GNU): More Flags for Globbing.
`GLOB_PERIOD`
  `glob.h` (GNU): More Flags for Globbing.
`glob_t`
  `glob.h` (POSIX.2): Calling Glob.
`GLOB_TILDE`
  `glob.h` (GNU): More Flags for Globbing.
`GLOB_TILDE_CHECK`
  `glob.h` (GNU): More Flags for Globbing.
`struct tm * gmtime (const time_t *`time`)`
  `time.h` (ISO): Broken-down Time.
`struct tm * gmtime_r (const time_t *`time`, struct tm *`resultp`)`
  `time.h` (POSIX.1c): Broken-down Time.
`_GNU_SOURCE`
  (GNU): Feature Test Macros.
`int grantpt (int` filedes`)`
  `stdlib.h` (SVID, XPG4.2): Allocation.
`int gsignal (int` signum`)`
  `signal.h` (SVID): Signaling Yourself.
`int gtty (int` filedes`, struct sgttyb *`attributes`)`
  `sgtty.h` (BSD): BSD Terminal Modes.
`char * hasmntopt (const struct mntent *`mnt`, const char *`opt`)`
  `mntent.h` (BSD): mtab.
`int hcreate (size_t` nel`)`
  `search.h` (SVID): Hash Search Function.
`int hcreate_r (size_t` nel`, struct hsearch_data *`htab`)`
  `search.h` (GNU): Hash Search Function.
`void hdestroy (void)`
  `search.h` (SVID): Hash Search Function.
`void hdestroy_r (struct hsearch_data *`htab`)`
  `search.h` (GNU): Hash Search Function.
`HOST_NOT_FOUND`
  `netdb.h` (BSD): Host Names.
`ENTRY * hsearch (ENTRY` item`, ACTION` action`)`
  `search.h` (SVID): Hash Search Function.
`int hsearch_r (ENTRY` item`, ACTION` action`, ENTRY **`retval`, struct hsearch_data *`htab`)`
  `search.h` (GNU): Hash Search Function.
`uint32_t htonl (uint32_t` hostlong`)`
  `netinet/in.h` (BSD): Byte Order.
`uint16_t htons (uint16_t` hostshort`)`
  `netinet/in.h` (BSD): Byte Order.
`double HUGE_VAL`
  `math.h` (ISO): Math Error Reporting.
`float HUGE_VALF`
  `math.h` (ISO): Math Error Reporting.
`long double HUGE_VALL`
  `math.h` (ISO): Math Error Reporting.
`tcflag_t HUPCL`
  `termios.h` (POSIX.1): Control Modes.
`double hypot (double` x`, double` y`)`
  `math.h` (ISO): Exponents and Logarithms.
`float hypotf (float` x`, float` y`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double hypotl (long double` x`, long double` y`)`
  `math.h` (ISO): Exponents and Logarithms.
`tcflag_t ICANON`
  `termios.h` (POSIX.1): Local Modes.
`size_t iconv (iconv_t` cd`, char **`inbuf`, size_t *`inbytesleft`, char **`outbuf`, size_t *`outbytesleft`)`
  `iconv.h` (XPG2): Generic Conversion Interface.
`int iconv_close (iconv_t` cd`)`
  `iconv.h` (XPG2): Generic Conversion Interface.
`iconv_t iconv_open (const char *`tocode`, const char *`fromcode`)`
  `iconv.h` (XPG2): Generic Conversion Interface.
`iconv_t`
  `iconv.h` (XPG2): Generic Conversion Interface.
`tcflag_t ICRNL`
  `termios.h` (POSIX.1): Input Modes.
`tcflag_t IEXTEN`
  `termios.h` (POSIX.1): Local Modes.
`void if_freenameindex (struct if_nameindex *`ptr`)`
  `net/if.h` (IPv6 basic API): Interface Naming.
`char * if_indextoname (unsigned int` ifindex`, char *`ifname`)`
  `net/if.h` (IPv6 basic API): Interface Naming.
`struct if_nameindex * if_nameindex (void)`
  `net/if.h` (IPv6 basic API): Interface Naming.
`unsigned int if_nametoindex (const char *`ifname`)`
  `net/if.h` (IPv6 basic API): Interface Naming.
`size_t IFNAMSIZ`
  `net/if.h` (net/if.h): Interface Naming.
`int IFTODT (mode_t` mode`)`
  `dirent.h` (BSD): Directory Entries.
`tcflag_t IGNBRK`
  `termios.h` (POSIX.1): Input Modes.
`tcflag_t IGNCR`
  `termios.h` (POSIX.1): Input Modes.
`tcflag_t IGNPAR`
  `termios.h` (POSIX.1): Input Modes.
`int ilogb (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`int ilogbf (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`int ilogbl (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`intmax_t imaxabs (intmax_t` number`)`
  `inttypes.h` (ISO): Absolute Value.
`tcflag_t IMAXBEL`
  `termios.h` (BSD): Input Modes.
`imaxdiv_t imaxdiv (intmax_t` numerator`, intmax_t` denominator`)`
  `inttypes.h` (ISO): Integer Division.
`imaxdiv_t`
  `inttypes.h` (ISO): Integer Division.
`struct in6_addr in6addr_any`
  `netinet/in.h` (IPv6 basic API): Host Address Data Type.
`struct in6_addr in6addr_loopback`
  `netinet/in.h` (IPv6 basic API): Host Address Data Type.
`uint32_t INADDR_ANY`
  `netinet/in.h` (BSD): Host Address Data Type.
`uint32_t INADDR_BROADCAST`
  `netinet/in.h` (BSD): Host Address Data Type.
`uint32_t INADDR_LOOPBACK`
  `netinet/in.h` (BSD): Host Address Data Type.
`uint32_t INADDR_NONE`
  `netinet/in.h` (BSD): Host Address Data Type.
`char * index (const char *`string`, int` c`)`
  `string.h` (BSD): Search Functions.
`uint32_t inet_addr (const char *`name`)`
  `arpa/inet.h` (BSD): Host Address Functions.
`int inet_aton (const char *`name`, struct in_addr *`addr`)`
  `arpa/inet.h` (BSD): Host Address Functions.
`uint32_t inet_lnaof (struct in_addr` addr`)`
  `arpa/inet.h` (BSD): Host Address Functions.
`struct in_addr inet_makeaddr (uint32_t` net`, uint32_t` local`)`
  `arpa/inet.h` (BSD): Host Address Functions.
`uint32_t inet_netof (struct in_addr` addr`)`
  `arpa/inet.h` (BSD): Host Address Functions.
`uint32_t inet_network (const char *`name`)`
  `arpa/inet.h` (BSD): Host Address Functions.
`char * inet_ntoa (struct in_addr` addr`)`
  `arpa/inet.h` (BSD): Host Address Functions.
`const char * inet_ntop (int` af`, const void *`cp`, char *`buf`, socklen_t` len`)`
  `arpa/inet.h` (IPv6 basic API): Host Address Functions.
`int inet_pton (int` af`, const char *`cp`, void *`buf`)`
  `arpa/inet.h` (IPv6 basic API): Host Address Functions.
`float INFINITY`
  `math.h` (ISO): Infinity and NaN.
`int initgroups (const char *`user`, gid_t` group`)`
  `grp.h` (BSD): Setting Groups.
`INIT_PROCESS`
  `utmp.h` (SVID): Manipulating the Database.
`INIT_PROCESS`
  `utmpx.h` (XPG4.2): XPG Functions.
`char * initstate (unsigned int` seed`, char *`state`, size_t` size`)`
  `stdlib.h` (BSD): BSD Random.
`int initstate_r (unsigned int` seed`, char *restrict` statebuf`, size_t` statelen`, struct random_data *restrict` buf`)`
  `stdlib.h` (GNU): BSD Random.
`tcflag_t INLCR`
  `termios.h` (POSIX.1): Input Modes.
`int innetgr (const char *`netgroup`, const char *`host`, const char *`user`, const char *`domain`)`
  `netdb.h` (BSD): Netgroup Membership.
`ino64_t`
  `sys/types.h` (Unix98): Attribute Meanings.
`ino_t`
  `sys/types.h` (POSIX.1): Attribute Meanings.
`tcflag_t INPCK`
  `termios.h` (POSIX.1): Input Modes.
`INT_MAX`
  `limits.h` (ISO): Range of Type.
`INT_MIN`
  `limits.h` (ISO): Range of Type.
`int ioctl (int` filedes`, int` command`, ...)`
  `sys/ioctl.h` (BSD): IOCTLs.
`int _IOFBF`
  `stdio.h` (ISO): Controlling Buffering.
`int _IOLBF`
  `stdio.h` (ISO): Controlling Buffering.
`int _IONBF`
  `stdio.h` (ISO): Controlling Buffering.
`int IPPORT_RESERVED`
  `netinet/in.h` (BSD): Ports.
`int IPPORT_USERRESERVED`
  `netinet/in.h` (BSD): Ports.
`int isalnum (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int isalpha (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int isascii (int` c`)`
  `ctype.h` (SVID, BSD): Classification of Characters.
`int isatty (int` filedes`)`
  `unistd.h` (POSIX.1): Is It a Terminal.
`int isblank (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int iscntrl (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int isdigit (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int isfinite (`float-type x`)`
  `math.h` (ISO): Floating Point Classes.
`int isgraph (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int isgreater (`real-floating x`,` real-floating y`)`
  `math.h` (ISO): FP Comparison Functions.
`int isgreaterequal (`real-floating x`,` real-floating y`)`
  `math.h` (ISO): FP Comparison Functions.
`tcflag_t ISIG`
  `termios.h` (POSIX.1): Local Modes.
`int isinf (double` x`)`
  `math.h` (BSD): Floating Point Classes.
`int isinff (float` x`)`
  `math.h` (BSD): Floating Point Classes.
`int isinfl (long double` x`)`
  `math.h` (BSD): Floating Point Classes.
`int isless (`real-floating x`,` real-floating y`)`
  `math.h` (ISO): FP Comparison Functions.
`int islessequal (`real-floating x`,` real-floating y`)`
  `math.h` (ISO): FP Comparison Functions.
`int islessgreater (`real-floating x`,` real-floating y`)`
  `math.h` (ISO): FP Comparison Functions.
`int islower (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int isnan (`float-type x`)`
  `math.h` (ISO): Floating Point Classes.
`int isnan (double` x`)`
  `math.h` (BSD): Floating Point Classes.
`int isnanf (float` x`)`
  `math.h` (BSD): Floating Point Classes.
`int isnanl (long double` x`)`
  `math.h` (BSD): Floating Point Classes.
`int isnormal (`float-type x`)`
  `math.h` (ISO): Floating Point Classes.
`_ISOC99_SOURCE`
  (GNU): Feature Test Macros.
`int isprint (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int ispunct (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int issignaling (`float-type x`)`
  `math.h` (GNU): Floating Point Classes.
`int isspace (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`tcflag_t ISTRIP`
  `termios.h` (POSIX.1): Input Modes.
`int isunordered (`real-floating x`,` real-floating y`)`
  `math.h` (ISO): FP Comparison Functions.
`int isupper (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`int iswalnum (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswalpha (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswblank (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswcntrl (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswctype (wint_t` wc`, wctype_t` desc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswdigit (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswgraph (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswlower (wint_t` wc`)`
  `ctype.h` (ISO): Classification of Wide Characters.
`int iswprint (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswpunct (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswspace (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswupper (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int iswxdigit (wint_t` wc`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`int isxdigit (int` c`)`
  `ctype.h` (ISO): Classification of Characters.
`ITIMER_PROF`
  `sys/time.h` (BSD): Setting an Alarm.
`ITIMER_REAL`
  `sys/time.h` (BSD): Setting an Alarm.
`ITIMER_VIRTUAL`
  `sys/time.h` (BSD): Setting an Alarm.
`tcflag_t IXANY`
  `termios.h` (BSD): Input Modes.
`tcflag_t IXOFF`
  `termios.h` (POSIX.1): Input Modes.
`tcflag_t IXON`
  `termios.h` (POSIX.1): Input Modes.
`double j0 (double` x`)`
  `math.h` (SVID): Special Functions.
`float j0f (float` x`)`
  `math.h` (SVID): Special Functions.
`long double j0l (long double` x`)`
  `math.h` (SVID): Special Functions.
`double j1 (double` x`)`
  `math.h` (SVID): Special Functions.
`float j1f (float` x`)`
  `math.h` (SVID): Special Functions.
`long double j1l (long double` x`)`
  `math.h` (SVID): Special Functions.
`jmp_buf`
  `setjmp.h` (ISO): Non-Local Details.
`double jn (int` n`, double` x`)`
  `math.h` (SVID): Special Functions.
`float jnf (int` n`, float` x`)`
  `math.h` (SVID): Special Functions.
`long double jnl (int` n`, long double` x`)`
  `math.h` (SVID): Special Functions.
`long int jrand48 (unsigned short int` xsubi`[3])`
  `stdlib.h` (SVID): SVID Random.
`int jrand48_r (unsigned short int` xsubi`[3], struct drand48_data *`buffer`, long int *`result`)`
  `stdlib.h` (GNU): SVID Random.
`int kill (pid_t` pid`, int` signum`)`
  `signal.h` (POSIX.1): Signaling Another Process.
`int killpg (int` pgid`, int` signum`)`
  `signal.h` (BSD): Signaling Another Process.
`char * l64a (long int` n`)`
  `stdlib.h` (XPG): Encode Binary Data.
`long int labs (long int` number`)`
  `stdlib.h` (ISO): Absolute Value.
`LANG`
  `locale.h` (ISO): Locale Categories.
`LC_ALL`
  `locale.h` (ISO): Locale Categories.
`LC_COLLATE`
  `locale.h` (ISO): Locale Categories.
`LC_CTYPE`
  `locale.h` (ISO): Locale Categories.
`LC_MESSAGES`
  `locale.h` (XOPEN): Locale Categories.
`LC_MONETARY`
  `locale.h` (ISO): Locale Categories.
`LC_NUMERIC`
  `locale.h` (ISO): Locale Categories.
`void lcong48 (unsigned short int` param`[7])`
  `stdlib.h` (SVID): SVID Random.
`int lcong48_r (unsigned short int` param`[7], struct drand48_data *`buffer`)`
  `stdlib.h` (GNU): SVID Random.
`int L_ctermid`
  `stdio.h` (POSIX.1): Identifying the Terminal.
`LC_TIME`
  `locale.h` (ISO): Locale Categories.
`int L_cuserid`
  `stdio.h` (POSIX.1): Who Logged In.
`double ldexp (double` value`, int` exponent`)`
  `math.h` (ISO): Normalization Functions.
`float ldexpf (float` value`, int` exponent`)`
  `math.h` (ISO): Normalization Functions.
`long double ldexpl (long double` value`, int` exponent`)`
  `math.h` (ISO): Normalization Functions.
`ldiv_t ldiv (long int` numerator`, long int` denominator`)`
  `stdlib.h` (ISO): Integer Division.
`ldiv_t`
  `stdlib.h` (ISO): Integer Division.
`void * lfind (const void *`key`, const void *`base`, size_t *`nmemb`, size_t` size`, comparison_fn_t` compar`)`
  `search.h` (SVID): Array Search Function.
`double lgamma (double` x`)`
  `math.h` (SVID): Special Functions.
`float lgammaf (float` x`)`
  `math.h` (SVID): Special Functions.
`float lgammaf_r (float` x`, int *`signp`)`
  `math.h` (XPG): Special Functions.
`long double lgammal (long double` x`)`
  `math.h` (SVID): Special Functions.
`long double lgammal_r (long double` x`, int *`signp`)`
  `math.h` (XPG): Special Functions.
`double lgamma_r (double` x`, int *`signp`)`
  `math.h` (XPG): Special Functions.
`L_INCR`
  `sys/file.h` (BSD): File Positioning.
`int LINE_MAX`
  `limits.h` (POSIX.2): Utility Limits.
`int link (const char *`oldname`, const char *`newname`)`
  `unistd.h` (POSIX.1): Hard Links.
`int LINK_MAX`
  `limits.h`, `(optional)` (POSIX.1): Limits for Files.
`int lio_listio (int` mode`, struct aiocb *const` list`[], int` nent`, struct sigevent *`sig`)`
  `aio.h` (POSIX.1b): Asynchronous Reads/Writes.
`int lio_listio64 (int` mode`, struct aiocb64 *const` list`[], int` nent`, struct sigevent *`sig`)`
  `aio.h` (Unix98): Asynchronous Reads/Writes.
`int listen (int` socket`, int` n`)`
  `sys/socket.h` (BSD): Listening.
`long long int llabs (long long int` number`)`
  `stdlib.h` (ISO): Absolute Value.
`lldiv_t lldiv (long long int` numerator`, long long int` denominator`)`
  `stdlib.h` (ISO): Integer Division.
`lldiv_t`
  `stdlib.h` (ISO): Integer Division.
`LLONG_MAX`
  `limits.h` (ISO): Range of Type.
`LLONG_MIN`
  `limits.h` (ISO): Range of Type.
`long long int llrint (double` x`)`
  `math.h` (ISO): Rounding Functions.
`long long int llrintf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long long int llrintl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`long long int llround (double` x`)`
  `math.h` (ISO): Rounding Functions.
`long long int llroundf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long long int llroundl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`struct lconv * localeconv (void)`
  `locale.h` (ISO): The Lame Way to Locale Data.
`struct tm * localtime (const time_t *`time`)`
  `time.h` (ISO): Broken-down Time.
`struct tm * localtime_r (const time_t *`time`, struct tm *`resultp`)`
  `time.h` (POSIX.1c): Broken-down Time.
`double log (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`double log10 (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float log10f (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double log10l (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`double log1p (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float log1pf (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double log1pl (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`double log2 (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float log2f (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double log2l (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`double logb (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float logbf (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double logbl (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float logf (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`void login (const struct utmp *`entry`)`
  `utmp.h` (BSD): Logging In and Out.
`LOGIN_PROCESS`
  `utmp.h` (SVID): Manipulating the Database.
`LOGIN_PROCESS`
  `utmpx.h` (XPG4.2): XPG Functions.
`int login_tty (int` filedes`)`
  `utmp.h` (BSD): Logging In and Out.
`long double logl (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`int logout (const char *`ut_line`)`
  `utmp.h` (BSD): Logging In and Out.
`void logwtmp (const char *`ut_line`, const char *`ut_name`, const char *`ut_host`)`
  `utmp.h` (BSD): Logging In and Out.
`void longjmp (jmp_buf` state`, int` value`)`
  `setjmp.h` (ISO): Non-Local Details.
`LONG_LONG_MAX`
  `limits.h` (GNU): Range of Type.
`LONG_LONG_MIN`
  `limits.h` (GNU): Range of Type.
`LONG_MAX`
  `limits.h` (ISO): Range of Type.
`LONG_MIN`
  `limits.h` (ISO): Range of Type.
`long int lrand48 (void)`
  `stdlib.h` (SVID): SVID Random.
`int lrand48_r (struct drand48_data *`buffer`, long int *`result`)`
  `stdlib.h` (GNU): SVID Random.
`long int lrint (double` x`)`
  `math.h` (ISO): Rounding Functions.
`long int lrintf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long int lrintl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`long int lround (double` x`)`
  `math.h` (ISO): Rounding Functions.
`long int lroundf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long int lroundl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`void * lsearch (const void *`key`, void *`base`, size_t *`nmemb`, size_t` size`, comparison_fn_t` compar`)`
  `search.h` (SVID): Array Search Function.
`off_t lseek (int` filedes`, off_t` offset`, int` whence`)`
  `unistd.h` (POSIX.1): File Position Primitive.
`off64_t lseek64 (int` filedes`, off64_t` offset`, int` whence`)`
  `unistd.h` (Unix98): File Position Primitive.
`L_SET`
  `sys/file.h` (BSD): File Positioning.
`int lstat (const char *`filename`, struct stat *`buf`)`
  `sys/stat.h` (BSD): Reading Attributes.
`int lstat64 (const char *`filename`, struct stat64 *`buf`)`
  `sys/stat.h` (Unix98): Reading Attributes.
`int L_tmpnam`
  `stdio.h` (ISO): Temporary Files.
`int lutimes (const char *`filename`, const struct timeval` tvp`[2]``)`
  `sys/time.h` (BSD): File Times.
`L_XTND`
  `sys/file.h` (BSD): File Positioning.
`int madvise (void *`addr`, size_t` length`, int` advice`)`
  `sys/mman.h` (POSIX): Memory-mapped I/O.
`void makecontext (ucontext_t *`ucp`, void (*`func`) (void), int` argc`, ...)`
  `ucontext.h` (SVID): System V contexts.
`struct mallinfo mallinfo (void)`
  `malloc.h` (SVID): Statistics of Malloc.
`void * malloc (size_t` size`)`
  `malloc.h`, `stdlib.h` (ISO): Basic Allocation.
`__malloc_hook`
  `malloc.h` (GNU): Hooks for Malloc.
`__malloc_initialize_hook`
  `malloc.h` (GNU): Hooks for Malloc.
`int MAX_CANON`
  `limits.h` (POSIX.1): Limits for Files.
`int MAX_INPUT`
  `limits.h` (POSIX.1): Limits for Files.
`int MAXNAMLEN`
  `dirent.h` (BSD): Limits for Files.
`int MAXSYMLINKS`
  `sys/param.h` (BSD): Symbolic Links.
`int MB_CUR_MAX`
  `stdlib.h` (ISO): Selecting the Conversion.
`int mblen (const char *`string`, size_t` size`)`
  `stdlib.h` (ISO): Non-reentrant Character Conversion.
`int MB_LEN_MAX`
  `limits.h` (ISO): Selecting the Conversion.
`size_t mbrlen (const char *restrict` s`, size_t` n`, mbstate_t *`ps`)`
  `wchar.h` (ISO): Converting a Character.
`size_t mbrtowc (wchar_t *restrict` pwc`, const char *restrict` s`, size_t` n`, mbstate_t *restrict` ps`)`
  `wchar.h` (ISO): Converting a Character.
`int mbsinit (const mbstate_t *`ps`)`
  `wchar.h` (ISO): Keeping the state.
`size_t mbsnrtowcs (wchar_t *restrict` dst`, const char **restrict` src`, size_t` nmc`, size_t` len`, mbstate_t *restrict` ps`)`
  `wchar.h` (GNU): Converting Strings.
`size_t mbsrtowcs (wchar_t *restrict` dst`, const char **restrict` src`, size_t` len`, mbstate_t *restrict` ps`)`
  `wchar.h` (ISO): Converting Strings.
`mbstate_t`
  `wchar.h` (ISO): Keeping the state.
`size_t mbstowcs (wchar_t *`wstring`, const char *`string`, size_t` size`)`
  `stdlib.h` (ISO): Non-reentrant String Conversion.
`int mbtowc (wchar_t *restrict` result`, const char *restrict` string`, size_t` size`)`
  `stdlib.h` (ISO): Non-reentrant Character Conversion.
`int mcheck (void (*`abortfn`) (enum mcheck_status` status`))`
  `mcheck.h` (GNU): Heap Consistency Checking.
`tcflag_t MDMBUF`
  `termios.h` (BSD): Control Modes.
`void * memalign (size_t` boundary`, size_t` size`)`
  `malloc.h` (BSD): Aligned Memory Blocks.
`__memalign_hook`
  `malloc.h` (GNU): Hooks for Malloc.
`void * memccpy (void *restrict` to`, const void *restrict` from`, int` c`, size_t` size`)`
  `string.h` (SVID): Copying and Concatenation.
`void * memchr (const void *`block`, int` c`, size_t` size`)`
  `string.h` (ISO): Search Functions.
`int memcmp (const void *`a1`, const void *`a2`, size_t` size`)`
  `string.h` (ISO): String/Array Comparison.
`void * memcpy (void *restrict` to`, const void *restrict` from`, size_t` size`)`
  `string.h` (ISO): Copying and Concatenation.
`void * memfrob (void *`mem`, size_t` length`)`
  `string.h` (GNU): Trivial Encryption.
`void * memmem (const void *`haystack`, size_t` haystack-len`,
const void *`needle`, size_t` needle-len`)`
  `string.h` (GNU): Search Functions.
`void * memmove (void *`to`, const void *`from`, size_t` size`)`
  `string.h` (ISO): Copying and Concatenation.
`void * mempcpy (void *restrict` to`, const void *restrict` from`, size_t` size`)`
  `string.h` (GNU): Copying and Concatenation.
`void * memrchr (const void *`block`, int` c`, size_t` size`)`
  `string.h` (GNU): Search Functions.
`void * memset (void *`block`, int` c`, size_t` size`)`
  `string.h` (ISO): Copying and Concatenation.
`int mkdir (const char *`filename`, mode_t` mode`)`
  `sys/stat.h` (POSIX.1): Creating Directories.
`char * mkdtemp (char *`template`)`
  `stdlib.h` (BSD): Temporary Files.
`int mkfifo (const char *`filename`, mode_t` mode`)`
  `sys/stat.h` (POSIX.1): FIFO Special Files.
`int mknod (const char *`filename`, mode_t` mode`, dev_t` dev`)`
  `sys/stat.h` (BSD): Making Special Files.
`int mkstemp (char *`template`)`
  `stdlib.h` (BSD): Temporary Files.
`char * mktemp (char *`template`)`
  `stdlib.h` (Unix): Temporary Files.
`time_t mktime (struct tm *`brokentime`)`
  `time.h` (ISO): Broken-down Time.
`int mlock (const void *`addr`, size_t` len`)`
  `sys/mman.h` (POSIX.1b): Page Lock Functions.
`int mlockall (int` flags`)`
  `sys/mman.h` (POSIX.1b): Page Lock Functions.
`void * mmap (void *`address`, size_t` length`, int` protect`, int` flags`, int` filedes`, off_t` offset`)`
  `sys/mman.h` (POSIX): Memory-mapped I/O.
`void * mmap64 (void *`address`, size_t` length`, int` protect`, int` flags`, int` filedes`, off64_t` offset`)`
  `sys/mman.h` (LFS): Memory-mapped I/O.
`mode_t`
  `sys/types.h` (POSIX.1): Attribute Meanings.
`double modf (double` value`, double *`integer-part`)`
  `math.h` (ISO): Rounding Functions.
`float modff (float` value`, float *`integer-part`)`
  `math.h` (ISO): Rounding Functions.
`long double modfl (long double` value`, long double *`integer-part`)`
  `math.h` (ISO): Rounding Functions.
`int mount (const char *`special_file`, const char *`dir`, const char *`fstype`, unsigned long int` options`, const void *`data`)`
  `sys/mount.h` (SVID, BSD): Mount-Unmount-Remount.
`long int mrand48 (void)`
  `stdlib.h` (SVID): SVID Random.
`int mrand48_r (struct drand48_data *`buffer`, long int *`result`)`
  `stdlib.h` (GNU): SVID Random.
`void * mremap (void *`address`, size_t` length`, size_t` new_length`, int` flag`)`
  `sys/mman.h` (GNU): Memory-mapped I/O.
`int MSG_DONTROUTE`
  `sys/socket.h` (BSD): Socket Data Options.
`int MSG_OOB`
  `sys/socket.h` (BSD): Socket Data Options.
`int MSG_PEEK`
  `sys/socket.h` (BSD): Socket Data Options.
`int msync (void *`address`, size_t` length`, int` flags`)`
  `sys/mman.h` (POSIX): Memory-mapped I/O.
`void mtrace (void)`
  `mcheck.h` (GNU): Tracing malloc.
`int munlock (const void *`addr`, size_t` len`)`
  `sys/mman.h` (POSIX.1b): Page Lock Functions.
`int munlockall (void)`
  `sys/mman.h` (POSIX.1b): Page Lock Functions.
`int munmap (void *`addr`, size_t` length`)`
  `sys/mman.h` (POSIX): Memory-mapped I/O.
`void muntrace (void)`
  `mcheck.h` (GNU): Tracing malloc.
`int NAME_MAX`
  `limits.h` (POSIX.1): Limits for Files.
`float NAN`
  `math.h` (GNU): Infinity and NaN.
`double nan (const char *`tagp`)`
  `math.h` (ISO): FP Bit Twiddling.
`float nanf (const char *`tagp`)`
  `math.h` (ISO): FP Bit Twiddling.
`long double nanl (const char *`tagp`)`
  `math.h` (ISO): FP Bit Twiddling.
`int nanosleep (const struct timespec *`requested_time`, struct timespec *`remaining`)`
  `time.h` (POSIX.1): Sleeping.
`int NCCS`
  `termios.h` (POSIX.1): Mode Data Types.
`double nearbyint (double` x`)`
  `math.h` (ISO): Rounding Functions.
`float nearbyintf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long double nearbyintl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`NEW_TIME`
  `utmp.h` (SVID): Manipulating the Database.
`NEW_TIME`
  `utmpx.h` (XPG4.2): XPG Functions.
`double nextafter (double` x`, double` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`float nextafterf (float` x`, float` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`long double nextafterl (long double` x`, long double` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`double nexttoward (double` x`, long double` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`float nexttowardf (float` x`, long double` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`long double nexttowardl (long double` x`, long double` y`)`
  `math.h` (ISO): FP Bit Twiddling.
`int nftw (const char *`filename`, __nftw_func_t` func`, int` descriptors`, int` flag`)`
  `ftw.h` (XPG4.2): Working with Directory Trees.
`int nftw64 (const char *`filename`, __nftw64_func_t` func`, int` descriptors`, int` flag`)`
  `ftw.h` (Unix98): Working with Directory Trees.
`__nftw64_func_t`
  `ftw.h` (GNU): Working with Directory Trees.
`__nftw_func_t`
  `ftw.h` (GNU): Working with Directory Trees.
`char * ngettext (const char *`msgid1`, const char *`msgid2`, unsigned long int` n`)`
  `libintl.h` (GNU): Advanced gettext functions.
`int NGROUPS_MAX`
  `limits.h` (POSIX.1): General Limits.
`int nice (int` increment`)`
  `unistd.h` (BSD): Traditional Scheduling Functions.
`nlink_t`
  `sys/types.h` (POSIX.1): Attribute Meanings.
`char * nl_langinfo (nl_item` item`)`
  `langinfo.h` (XOPEN): The Elegant and Fast Way.
`NO_ADDRESS`
  `netdb.h` (BSD): Host Names.
`tcflag_t NOFLSH`
  `termios.h` (POSIX.1): Local Modes.
`tcflag_t NOKERNINFO`
  `termios.h`, `(optional)` (BSD): Local Modes.
`NO_RECOVERY`
  `netdb.h` (BSD): Host Names.
`long int nrand48 (unsigned short int` xsubi`[3])`
  `stdlib.h` (SVID): SVID Random.
`int nrand48_r (unsigned short int` xsubi`[3], struct drand48_data *`buffer`, long int *`result`)`
  `stdlib.h` (GNU): SVID Random.
`int NSIG`
  `signal.h` (BSD): Standard Signals.
`uint32_t ntohl (uint32_t` netlong`)`
  `netinet/in.h` (BSD): Byte Order.
`uint16_t ntohs (uint16_t` netshort`)`
  `netinet/in.h` (BSD): Byte Order.
`int ntp_adjtime (struct timex *`tptr`)`
  `sys/timex.h` (GNU): High Accuracy Clock.
`int ntp_gettime (struct ntptimeval *`tptr`)`
  `sys/timex.h` (GNU): High Accuracy Clock.
`void * NULL`
  `stddef.h` (ISO): Null Pointer Constant.
`int O_ACCMODE`
  `fcntl.h` (POSIX.1): Access Modes.
`int O_APPEND`
  `fcntl.h` (POSIX.1): Operating Modes.
`int O_ASYNC`
  `fcntl.h` (BSD): Operating Modes.
`void obstack_1grow (struct obstack *`obstack-ptr`, char` c`)`
  `obstack.h` (GNU): Growing Objects.
`void obstack_1grow_fast (struct obstack *`obstack-ptr`, char` c`)`
  `obstack.h` (GNU): Extra Fast Growing.
`int obstack_alignment_mask (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Obstacks Data Alignment.
`void * obstack_alloc (struct obstack *`obstack-ptr`, int` size`)`
  `obstack.h` (GNU): Allocation in an Obstack.
`obstack_alloc_failed_handler`
  `obstack.h` (GNU): Preparing for Obstacks.
`void * obstack_base (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Status of an Obstack.
`void obstack_blank (struct obstack *`obstack-ptr`, int` size`)`
  `obstack.h` (GNU): Growing Objects.
`void obstack_blank_fast (struct obstack *`obstack-ptr`, int` size`)`
  `obstack.h` (GNU): Extra Fast Growing.
`int obstack_chunk_size (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Obstack Chunks.
`void * obstack_copy (struct obstack *`obstack-ptr`, void *`address`, int` size`)`
  `obstack.h` (GNU): Allocation in an Obstack.
`void * obstack_copy0 (struct obstack *`obstack-ptr`, void *`address`, int` size`)`
  `obstack.h` (GNU): Allocation in an Obstack.
`void * obstack_finish (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Growing Objects.
`void obstack_free (struct obstack *`obstack-ptr`, void *`object`)`
  `obstack.h` (GNU): Freeing Obstack Objects.
`void obstack_grow (struct obstack *`obstack-ptr`, void *`data`, int` size`)`
  `obstack.h` (GNU): Growing Objects.
`void obstack_grow0 (struct obstack *`obstack-ptr`, void *`data`, int` size`)`
  `obstack.h` (GNU): Growing Objects.
`int obstack_init (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Preparing for Obstacks.
`void obstack_int_grow (struct obstack *`obstack-ptr`, int` data`)`
  `obstack.h` (GNU): Growing Objects.
`void obstack_int_grow_fast (struct obstack *`obstack-ptr`, int` data`)`
  `obstack.h` (GNU): Extra Fast Growing.
`void * obstack_next_free (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Status of an Obstack.
`int obstack_object_size (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Growing Objects.
`int obstack_object_size (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Status of an Obstack.
`int obstack_printf (struct obstack *`obstack`, const char *`template`, ...)`
  `stdio.h` (GNU): Dynamic Output.
`void obstack_ptr_grow (struct obstack *`obstack-ptr`, void *`data`)`
  `obstack.h` (GNU): Growing Objects.
`void obstack_ptr_grow_fast (struct obstack *`obstack-ptr`, void *`data`)`
  `obstack.h` (GNU): Extra Fast Growing.
`int obstack_room (struct obstack *`obstack-ptr`)`
  `obstack.h` (GNU): Extra Fast Growing.
`int obstack_vprintf (struct obstack *`obstack`, const char *`template`, va_list` ap`)`
  `stdio.h` (GNU): Variable Arguments Output.
`int O_CREAT`
  `fcntl.h` (POSIX.1): Open-time Flags.
`int O_EXCL`
  `fcntl.h` (POSIX.1): Open-time Flags.
`int O_EXEC`
  `fcntl.h`, `(optional)` (GNU): Access Modes.
`int O_EXLOCK`
  `fcntl.h`, `(optional)` (BSD): Open-time Flags.
`off64_t`
  `sys/types.h` (Unix98): File Position Primitive.
`size_t offsetof (`type`,` member`)`
  `stddef.h` (ISO): Structure Measurement.
`off_t`
  `sys/types.h` (POSIX.1): File Position Primitive.
`int O_FSYNC`
  `fcntl.h` (BSD): Operating Modes.
`int O_IGNORE_CTTY`
  `fcntl.h`, `(optional)` (GNU): Open-time Flags.
`OLD_TIME`
  `utmp.h` (SVID): Manipulating the Database.
`OLD_TIME`
  `utmpx.h` (XPG4.2): XPG Functions.
`int O_NDELAY`
  `fcntl.h` (BSD): Operating Modes.
`int on_exit (void (*`function`)(int` status`, void *`arg`), void *`arg`)`
  `stdlib.h` (SunOS): Cleanups on Exit.
`tcflag_t ONLCR`
  `termios.h` (POSIX.1): Output Modes.
`int O_NOATIME`
  `fcntl.h` (GNU): Operating Modes.
`int O_NOCTTY`
  `fcntl.h` (POSIX.1): Open-time Flags.
`tcflag_t ONOEOT`
  `termios.h`, `(optional)` (BSD): Output Modes.
`int O_NOLINK`
  `fcntl.h`, `(optional)` (GNU): Open-time Flags.
`int O_NONBLOCK`
  `fcntl.h` (POSIX.1): Open-time Flags.
`int O_NONBLOCK`
  `fcntl.h` (POSIX.1): Operating Modes.
`int O_NOTRANS`
  `fcntl.h`, `(optional)` (GNU): Open-time Flags.
`int open (const char *`filename`, int` flags`[, mode_t` mode`])`
  `fcntl.h` (POSIX.1): Opening and Closing Files.
`int open64 (const char *`filename`, int` flags`[, mode_t` mode`])`
  `fcntl.h` (Unix98): Opening and Closing Files.
`DIR * opendir (const char *`dirname`)`
  `dirent.h` (POSIX.1): Opening a Directory.
`void openlog (const char *`ident`, int` option`, int` facility`)`
  `syslog.h` (BSD): openlog.
`int OPEN_MAX`
  `limits.h` (POSIX.1): General Limits.
`FILE * open_memstream (char **`ptr`, size_t *`sizeloc`)`
  `stdio.h` (GNU): String Streams.
`int openpty (int *`amaster`, int *`aslave`, char *`name`, const struct termios *`termp`, const struct winsize *`winp`)`
  `pty.h` (BSD): Pseudo-Terminal Pairs.
`tcflag_t OPOST`
  `termios.h` (POSIX.1): Output Modes.
`char * optarg`
  `unistd.h` (POSIX.2): Using Getopt.
`int opterr`
  `unistd.h` (POSIX.2): Using Getopt.
`int optind`
  `unistd.h` (POSIX.2): Using Getopt.
`OPTION_ALIAS`
  `argp.h` (GNU): Argp Option Flags.
`OPTION_ARG_OPTIONAL`
  `argp.h` (GNU): Argp Option Flags.
`OPTION_DOC`
  `argp.h` (GNU): Argp Option Flags.
`OPTION_HIDDEN`
  `argp.h` (GNU): Argp Option Flags.
`OPTION_NO_USAGE`
  `argp.h` (GNU): Argp Option Flags.
`int optopt`
  `unistd.h` (POSIX.2): Using Getopt.
`int O_RDONLY`
  `fcntl.h` (POSIX.1): Access Modes.
`int O_RDWR`
  `fcntl.h` (POSIX.1): Access Modes.
`int O_READ`
  `fcntl.h`, `(optional)` (GNU): Access Modes.
`int O_SHLOCK`
  `fcntl.h`, `(optional)` (BSD): Open-time Flags.
`int O_SYNC`
  `fcntl.h` (BSD): Operating Modes.
`int O_TRUNC`
  `fcntl.h` (POSIX.1): Open-time Flags.
`int O_WRITE`
  `fcntl.h`, `(optional)` (GNU): Access Modes.
`int O_WRONLY`
  `fcntl.h` (POSIX.1): Access Modes.
`tcflag_t OXTABS`
  `termios.h`, `(optional)` (BSD): Output Modes.
`PA_CHAR`
  `printf.h` (GNU): Parsing a Template String.
`PA_DOUBLE`
  `printf.h` (GNU): Parsing a Template String.
`PA_FLAG_LONG`
  `printf.h` (GNU): Parsing a Template String.
`PA_FLAG_LONG_DOUBLE`
  `printf.h` (GNU): Parsing a Template String.
`PA_FLAG_LONG_LONG`
  `printf.h` (GNU): Parsing a Template String.
`int PA_FLAG_MASK`
  `printf.h` (GNU): Parsing a Template String.
`PA_FLAG_PTR`
  `printf.h` (GNU): Parsing a Template String.
`PA_FLAG_SHORT`
  `printf.h` (GNU): Parsing a Template String.
`PA_FLOAT`
  `printf.h` (GNU): Parsing a Template String.
`PA_INT`
  `printf.h` (GNU): Parsing a Template String.
`PA_LAST`
  `printf.h` (GNU): Parsing a Template String.
`PA_POINTER`
  `printf.h` (GNU): Parsing a Template String.
`tcflag_t PARENB`
  `termios.h` (POSIX.1): Control Modes.
`tcflag_t PARMRK`
  `termios.h` (POSIX.1): Input Modes.
`tcflag_t PARODD`
  `termios.h` (POSIX.1): Control Modes.
`size_t parse_printf_format (const char *`template`, size_t` n`, int *`argtypes`)`
  `printf.h` (GNU): Parsing a Template String.
`PA_STRING`
  `printf.h` (GNU): Parsing a Template String.
`long int pathconf (const char *`filename`, int` parameter`)`
  `unistd.h` (POSIX.1): Pathconf.
`int PATH_MAX`
  `limits.h` (POSIX.1): Limits for Files.
`int pause (void)`
  `unistd.h` (POSIX.1): Using Pause.
`_PC_ASYNC_IO`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_CHOWN_RESTRICTED`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_FILESIZEBITS`
  `unistd.h` (LFS): Pathconf.
`_PC_LINK_MAX`
  `unistd.h` (POSIX.1): Pathconf.
`int pclose (FILE *`stream`)`
  `stdio.h` (POSIX.2, SVID, BSD): Pipe to a Subprocess.
`_PC_MAX_CANON`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_MAX_INPUT`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_NAME_MAX`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_NO_TRUNC`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_PATH_MAX`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_PIPE_BUF`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_PRIO_IO`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_REC_INCR_XFER_SIZE`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_REC_MAX_XFER_SIZE`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_REC_MIN_XFER_SIZE`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_REC_XFER_ALIGN`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_SYNC_IO`
  `unistd.h` (POSIX.1): Pathconf.
`_PC_VDISABLE`
  `unistd.h` (POSIX.1): Pathconf.
`tcflag_t PENDIN`
  `termios.h` (BSD): Local Modes.
`void perror (const char *`message`)`
  `stdio.h` (ISO): Error Messages.
`int PF_FILE`
  `sys/socket.h` (GNU): Local Namespace Details.
`int PF_INET`
  `sys/socket.h` (BSD): Internet Namespace.
`int PF_INET6`
  `sys/socket.h` (X/Open): Internet Namespace.
`int PF_LOCAL`
  `sys/socket.h` (POSIX): Local Namespace Details.
`int PF_UNIX`
  `sys/socket.h` (BSD): Local Namespace Details.
`pid_t`
  `sys/types.h` (POSIX.1): Process Identification.
`int pipe (int` filedes`[2]``)`
  `unistd.h` (POSIX.1): Creating a Pipe.
`int PIPE_BUF`
  `limits.h` (POSIX.1): Limits for Files.
`FILE * popen (const char *`command`, const char *`mode`)`
  `stdio.h` (POSIX.2, SVID, BSD): Pipe to a Subprocess.
`_POSIX2_BC_BASE_MAX`
  `limits.h` (POSIX.2): Utility Minimums.
`_POSIX2_BC_DIM_MAX`
  `limits.h` (POSIX.2): Utility Minimums.
`_POSIX2_BC_SCALE_MAX`
  `limits.h` (POSIX.2): Utility Minimums.
`_POSIX2_BC_STRING_MAX`
  `limits.h` (POSIX.2): Utility Minimums.
`int _POSIX2_C_DEV`
  `unistd.h` (POSIX.2): System Options.
`_POSIX2_COLL_WEIGHTS_MAX`
  `limits.h` (POSIX.2): Utility Minimums.
`long int _POSIX2_C_VERSION`
  `unistd.h` (POSIX.2): Version Supported.
`_POSIX2_EQUIV_CLASS_MAX`
  `limits.h` (POSIX.2): Utility Minimums.
`_POSIX2_EXPR_NEST_MAX`
  `limits.h` (POSIX.2): Utility Minimums.
`int _POSIX2_FORT_DEV`
  `unistd.h` (POSIX.2): System Options.
`int _POSIX2_FORT_RUN`
  `unistd.h` (POSIX.2): System Options.
`_POSIX2_LINE_MAX`
  `limits.h` (POSIX.2): Utility Minimums.
`int _POSIX2_LOCALEDEF`
  `unistd.h` (POSIX.2): System Options.
`_POSIX2_RE_DUP_MAX`
  `limits.h` (POSIX.2): Minimums.
`int _POSIX2_SW_DEV`
  `unistd.h` (POSIX.2): System Options.
`_POSIX_AIO_LISTIO_MAX`
  `limits.h` (POSIX.1): Minimums.
`_POSIX_AIO_MAX`
  `limits.h` (POSIX.1): Minimums.
`_POSIX_ARG_MAX`
  `limits.h` (POSIX.1): Minimums.
`_POSIX_CHILD_MAX`
  `limits.h` (POSIX.1): Minimums.
`int _POSIX_CHOWN_RESTRICTED`
  `unistd.h` (POSIX.1): Options for Files.
`_POSIX_C_SOURCE`
  (POSIX.2): Feature Test Macros.
`int _POSIX_JOB_CONTROL`
  `unistd.h` (POSIX.1): System Options.
`_POSIX_LINK_MAX`
  `limits.h` (POSIX.1): File Minimums.
`_POSIX_MAX_CANON`
  `limits.h` (POSIX.1): File Minimums.
`_POSIX_MAX_INPUT`
  `limits.h` (POSIX.1): File Minimums.
`int posix_memalign (void **`memptr`, size_t` alignment`, size_t` size`)`
  `stdlib.h` (POSIX): Aligned Memory Blocks.
`_POSIX_NAME_MAX`
  `limits.h` (POSIX.1): File Minimums.
`_POSIX_NGROUPS_MAX`
  `limits.h` (POSIX.1): Minimums.
`int _POSIX_NO_TRUNC`
  `unistd.h` (POSIX.1): Options for Files.
`_POSIX_OPEN_MAX`
  `limits.h` (POSIX.1): Minimums.
`_POSIX_PATH_MAX`
  `limits.h` (POSIX.1): File Minimums.
`_POSIX_PIPE_BUF`
  `limits.h` (POSIX.1): File Minimums.
`POSIX_REC_INCR_XFER_SIZE`
  `limits.h` (POSIX.1): File Minimums.
`POSIX_REC_MAX_XFER_SIZE`
  `limits.h` (POSIX.1): File Minimums.
`POSIX_REC_MIN_XFER_SIZE`
  `limits.h` (POSIX.1): File Minimums.
`POSIX_REC_XFER_ALIGN`
  `limits.h` (POSIX.1): File Minimums.
`int _POSIX_SAVED_IDS`
  `unistd.h` (POSIX.1): System Options.
`_POSIX_SOURCE`
  (POSIX.1): Feature Test Macros.
`_POSIX_SSIZE_MAX`
  `limits.h` (POSIX.1): Minimums.
`_POSIX_STREAM_MAX`
  `limits.h` (POSIX.1): Minimums.
`_POSIX_TZNAME_MAX`
  `limits.h` (POSIX.1): Minimums.
`unsigned char _POSIX_VDISABLE`
  `unistd.h` (POSIX.1): Options for Files.
`long int _POSIX_VERSION`
  `unistd.h` (POSIX.1): Version Supported.
`double pow (double` base`, double` power`)`
  `math.h` (ISO): Exponents and Logarithms.
`double pow10 (double` x`)`
  `math.h` (GNU): Exponents and Logarithms.
`float pow10f (float` x`)`
  `math.h` (GNU): Exponents and Logarithms.
`long double pow10l (long double` x`)`
  `math.h` (GNU): Exponents and Logarithms.
`float powf (float` base`, float` power`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double powl (long double` base`, long double` power`)`
  `math.h` (ISO): Exponents and Logarithms.
`ssize_t pread (int` filedes`, void *`buffer`, size_t` size`, off_t` offset`)`
  `unistd.h` (Unix98): I/O Primitives.
`ssize_t pread64 (int` filedes`, void *`buffer`, size_t` size`, off64_t` offset`)`
  `unistd.h` (Unix98): I/O Primitives.
`int printf (const char *`template`, ...)`
  `stdio.h` (ISO): Formatted Output Functions.
`printf_arginfo_function`
  `printf.h` (GNU): Defining the Output Handler.
`printf_function`
  `printf.h` (GNU): Defining the Output Handler.
`int printf_size (FILE *`fp`, const struct printf_info *`info`, const void *const *`args`)`
  `printf.h` (GNU): Predefined Printf Handlers.
`int printf_size_info (const struct printf_info *`info`, size_t` n`, int *`argtypes`)`
  `printf.h` (GNU): Predefined Printf Handlers.
`PRIO_MAX`
  `sys/resource.h` (BSD): Traditional Scheduling Functions.
`PRIO_MIN`
  `sys/resource.h` (BSD): Traditional Scheduling Functions.
`PRIO_PGRP`
  `sys/resource.h` (BSD): Traditional Scheduling Functions.
`PRIO_PROCESS`
  `sys/resource.h` (BSD): Traditional Scheduling Functions.
`PRIO_USER`
  `sys/resource.h` (BSD): Traditional Scheduling Functions.
`char * program_invocation_name`
  `errno.h` (GNU): Error Messages.
`char * program_invocation_short_name`
  `errno.h` (GNU): Error Messages.
`void psignal (int` signum`, const char *`message`)`
  `signal.h` (BSD): Signal Messages.
`char * P_tmpdir`
  `stdio.h` (SVID): Temporary Files.
`ptrdiff_t`
  `stddef.h` (ISO): Important Data Types.
`char * ptsname (int` filedes`)`
  `stdlib.h` (SVID, XPG4.2): Allocation.
`int ptsname_r (int` filedes`, char *`buf`, size_t` len`)`
  `stdlib.h` (GNU): Allocation.
`int putc (int` c`, FILE *`stream`)`
  `stdio.h` (ISO): Simple Output.
`int putchar (int` c`)`
  `stdio.h` (ISO): Simple Output.
`int putchar_unlocked (int` c`)`
  `stdio.h` (POSIX): Simple Output.
`int putc_unlocked (int` c`, FILE *`stream`)`
  `stdio.h` (POSIX): Simple Output.
`int putenv (char *`string`)`
  `stdlib.h` (SVID): Environment Access.
`int putpwent (const struct passwd *`p`, FILE *`stream`)`
  `pwd.h` (SVID): Writing a User Entry.
`int puts (const char *`s`)`
  `stdio.h` (ISO): Simple Output.
`struct utmp * pututline (const struct utmp *`utmp`)`
  `utmp.h` (SVID): Manipulating the Database.
`struct utmpx * pututxline (const struct utmpx *`utmp`)`
  `utmpx.h` (XPG4.2): XPG Functions.
`int putw (int` w`, FILE *`stream`)`
  `stdio.h` (SVID): Simple Output.
`wint_t putwc (wchar_t` wc`, FILE *`stream`)`
  `wchar.h` (ISO): Simple Output.
`wint_t putwchar (wchar_t` wc`)`
  `wchar.h` (ISO): Simple Output.
`wint_t putwchar_unlocked (wchar_t` wc`)`
  `wchar.h` (GNU): Simple Output.
`wint_t putwc_unlocked (wchar_t` wc`, FILE *`stream`)`
  `wchar.h` (GNU): Simple Output.
`ssize_t pwrite (int` filedes`, const void *`buffer`, size_t` size`, off_t` offset`)`
  `unistd.h` (Unix98): I/O Primitives.
`ssize_t pwrite64 (int` filedes`, const void *`buffer`, size_t` size`, off64_t` offset`)`
  `unistd.h` (Unix98): I/O Primitives.
`char * qecvt (long double` value`, int` ndigit`, int *`decpt`, int *`neg`)`
  `stdlib.h` (GNU): System V Number Conversion.
`int qecvt_r (long double` value`, int` ndigit`, int *`decpt`, int *`neg`, char *`buf`, size_t` len`)`
  `stdlib.h` (GNU): System V Number Conversion.
`char * qfcvt (long double` value`, int` ndigit`, int *`decpt`, int *`neg`)`
  `stdlib.h` (GNU): System V Number Conversion.
`int qfcvt_r (long double` value`, int` ndigit`, int *`decpt`, int *`neg`, char *`buf`, size_t` len`)`
  `stdlib.h` (GNU): System V Number Conversion.
`char * qgcvt (long double` value`, int` ndigit`, char *`buf`)`
  `stdlib.h` (GNU): System V Number Conversion.
`void qsort (void *`array`, size_t` count`, size_t` size`, comparison_fn_t` compare`)`
  `stdlib.h` (ISO): Array Sort Function.
`int raise (int` signum`)`
  `signal.h` (ISO): Signaling Yourself.
`int rand (void)`
  `stdlib.h` (ISO): ISO Random.
`int RAND_MAX`
  `stdlib.h` (ISO): ISO Random.
`long int random (void)`
  `stdlib.h` (BSD): BSD Random.
`int random_r (struct random_data *restrict` buf`, int32_t *restrict` result`)`
  `stdlib.h` (GNU): BSD Random.
`int rand_r (unsigned int *`seed`)`
  `stdlib.h` (POSIX.1): ISO Random.
`void * rawmemchr (const void *`block`, int` c`)`
  `string.h` (GNU): Search Functions.
`ssize_t read (int` filedes`, void *`buffer`, size_t` size`)`
  `unistd.h` (POSIX.1): I/O Primitives.
`struct dirent * readdir (DIR *`dirstream`)`
  `dirent.h` (POSIX.1): Reading/Closing Directory.
`struct dirent64 * readdir64 (DIR *`dirstream`)`
  `dirent.h` (LFS): Reading/Closing Directory.
`int readdir64_r (DIR *`dirstream`, struct dirent64 *`entry`, struct dirent64 **`result`)`
  `dirent.h` (LFS): Reading/Closing Directory.
`int readdir_r (DIR *`dirstream`, struct dirent *`entry`, struct dirent **`result`)`
  `dirent.h` (GNU): Reading/Closing Directory.
`ssize_t readlink (const char *`filename`, char *`buffer`, size_t` size`)`
  `unistd.h` (BSD): Symbolic Links.
`ssize_t readv (int` filedes`, const struct iovec *`vector`, int` count`)`
  `sys/uio.h` (BSD): Scatter-Gather.
`void * realloc (void *`ptr`, size_t` newsize`)`
  `malloc.h`, `stdlib.h` (ISO): Changing Block Size.
`__realloc_hook`
  `malloc.h` (GNU): Hooks for Malloc.
`char * realpath (const char *restrict` name`, char *restrict` resolved`)`
  `stdlib.h` (XPG): Symbolic Links.
`ssize_t recv (int` socket`, void *`buffer`, size_t` size`, int` flags`)`
  `sys/socket.h` (BSD): Receiving Data.
`ssize_t recvfrom (int` socket`, void *`buffer`, size_t` size`, int` flags`, struct sockaddr *`addr`, socklen_t *`length-ptr`)`
  `sys/socket.h` (BSD): Receiving Datagrams.
`ssize_t recvmsg (int` socket`, struct msghdr *`message`, int` flags`)`
  `sys/socket.h` (BSD): Receiving Datagrams.
`int RE_DUP_MAX`
  `limits.h` (POSIX.2): General Limits.
`_REENTRANT`
  (GNU): Feature Test Macros.
`REG_BADBR`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_BADPAT`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_BADRPT`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`int regcomp (regex_t *restrict` compiled`, const char *restrict` pattern`, int` cflags`)`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_EBRACE`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_EBRACK`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_ECOLLATE`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_ECTYPE`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_EESCAPE`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_EPAREN`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_ERANGE`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`size_t regerror (int` errcode`, const regex_t *restrict` compiled`, char *restrict` buffer`, size_t` length`)`
  `regex.h` (POSIX.2): Regexp Cleanup.
`REG_ESPACE`
  `regex.h` (POSIX.2): Matching POSIX Regexps.
`REG_ESPACE`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_ESUBREG`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`int regexec (const regex_t *restrict` compiled`, const char *restrict` string`, size_t` nmatch`, regmatch_t` matchptr`[restrict], int` eflags`)`
  `regex.h` (POSIX.2): Matching POSIX Regexps.
`regex_t`
  `regex.h` (POSIX.2): POSIX Regexp Compilation.
`REG_EXTENDED`
  `regex.h` (POSIX.2): Flags for POSIX Regexps.
`void regfree (regex_t *`compiled`)`
  `regex.h` (POSIX.2): Regexp Cleanup.
`REG_ICASE`
  `regex.h` (POSIX.2): Flags for POSIX Regexps.
`int register_printf_function (int` spec`, printf_function` handler-function`, printf_arginfo_function` arginfo-function`)`
  `printf.h` (GNU): Registering New Conversions.
`regmatch_t`
  `regex.h` (POSIX.2): Regexp Subexpressions.
`REG_NEWLINE`
  `regex.h` (POSIX.2): Flags for POSIX Regexps.
`REG_NOMATCH`
  `regex.h` (POSIX.2): Matching POSIX Regexps.
`REG_NOSUB`
  `regex.h` (POSIX.2): Flags for POSIX Regexps.
`REG_NOTBOL`
  `regex.h` (POSIX.2): Matching POSIX Regexps.
`REG_NOTEOL`
  `regex.h` (POSIX.2): Matching POSIX Regexps.
`regoff_t`
  `regex.h` (POSIX.2): Regexp Subexpressions.
`double remainder (double` numerator`, double` denominator`)`
  `math.h` (BSD): Remainder Functions.
`float remainderf (float` numerator`, float` denominator`)`
  `math.h` (BSD): Remainder Functions.
`long double remainderl (long double` numerator`, long double` denominator`)`
  `math.h` (BSD): Remainder Functions.
`int remove (const char *`filename`)`
  `stdio.h` (ISO): Deleting Files.
`int rename (const char *`oldname`, const char *`newname`)`
  `stdio.h` (ISO): Renaming Files.
`void rewind (FILE *`stream`)`
  `stdio.h` (ISO): File Positioning.
`void rewinddir (DIR *`dirstream`)`
  `dirent.h` (POSIX.1): Random Access Directory.
`char * rindex (const char *`string`, int` c`)`
  `string.h` (BSD): Search Functions.
`double rint (double` x`)`
  `math.h` (ISO): Rounding Functions.
`float rintf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long double rintl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`rlim_t RLIM_INFINITY`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_AS`
  `sys/resource.h` (Unix98): Limits on Resources.
`RLIMIT_CORE`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_CPU`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_DATA`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_FSIZE`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_MEMLOCK`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_NOFILE`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_NPROC`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_RSS`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIMIT_STACK`
  `sys/resource.h` (BSD): Limits on Resources.
`RLIM_NLIMITS`
  `sys/resource.h` (BSD): Limits on Resources.
`int rmdir (const char *`filename`)`
  `unistd.h` (POSIX.1): Deleting Files.
`int R_OK`
  `unistd.h` (POSIX.1): Testing File Access.
`double round (double` x`)`
  `math.h` (ISO): Rounding Functions.
`float roundf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long double roundl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`int rpmatch (const char *`response`)`
  `stdlib.h` (stdlib.h): Yes-or-No Questions.
`RUN_LVL`
  `utmp.h` (SVID): Manipulating the Database.
`RUN_LVL`
  `utmpx.h` (XPG4.2): XPG Functions.
`RUSAGE_CHILDREN`
  `sys/resource.h` (BSD): Resource Usage.
`RUSAGE_SELF`
  `sys/resource.h` (BSD): Resource Usage.
`int SA_NOCLDSTOP`
  `signal.h` (POSIX.1): Flags for Sigaction.
`int SA_ONSTACK`
  `signal.h` (BSD): Flags for Sigaction.
`int SA_RESTART`
  `signal.h` (BSD): Flags for Sigaction.
`void *sbrk (ptrdiff_t` delta`)`
  `unistd.h` (BSD): Resizing the Data Segment.
`_SC_2_C_DEV`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_2_FORT_DEV`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_2_FORT_RUN`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_2_LOCALEDEF`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_2_SW_DEV`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_2_VERSION`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_AIO_LISTIO_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_AIO_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_AIO_PRIO_DELTA_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`double scalb (double` value`, double` exponent`)`
  `math.h` (BSD): Normalization Functions.
`float scalbf (float` value`, float` exponent`)`
  `math.h` (BSD): Normalization Functions.
`long double scalbl (long double` value`, long double` exponent`)`
  `math.h` (BSD): Normalization Functions.
`double scalbln (double` x`, long int` n`)`
  `math.h` (BSD): Normalization Functions.
`float scalblnf (float` x`, long int` n`)`
  `math.h` (BSD): Normalization Functions.
`long double scalblnl (long double` x`, long int` n`)`
  `math.h` (BSD): Normalization Functions.
`double scalbn (double` x`, int` n`)`
  `math.h` (BSD): Normalization Functions.
`float scalbnf (float` x`, int` n`)`
  `math.h` (BSD): Normalization Functions.
`long double scalbnl (long double` x`, int` n`)`
  `math.h` (BSD): Normalization Functions.
`int scandir (const char *`dir`, struct dirent ***`namelist`, int (*`selector`) (const struct dirent *), int (*`cmp`) (const struct dirent **, const struct dirent **))`
  `dirent.h` (BSD/SVID): Scanning Directory Content.
`int scandir64 (const char *`dir`, struct dirent64 ***`namelist`, int (*`selector`) (const struct dirent64 *), int (*`cmp`) (const struct dirent64 **, const struct dirent64 **))`
  `dirent.h` (GNU): Scanning Directory Content.
`int scanf (const char *`template`, ...)`
  `stdio.h` (ISO): Formatted Input Functions.
`_SC_ARG_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_ASYNCHRONOUS_IO`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_ATEXIT_MAX`
  `unistd.h` (GNU): Constants for Sysconf.
`_SC_AVPHYS_PAGES`
  `unistd.h` (GNU): Constants for Sysconf.
`_SC_BC_BASE_MAX`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_BC_DIM_MAX`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_BC_SCALE_MAX`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_BC_STRING_MAX`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_CHAR_BIT`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_CHARCLASS_NAME_MAX`
  `unistd.h` (GNU): Constants for Sysconf.
`_SC_CHAR_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_CHAR_MIN`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_CHILD_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_CLK_TCK`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_COLL_WEIGHTS_MAX`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_DELAYTIMER_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_EQUIV_CLASS_MAX`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_EXPR_NEST_MAX`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_FSYNC`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_GETGR_R_SIZE_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_GETPW_R_SIZE_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`SCHAR_MAX`
  `limits.h` (ISO): Range of Type.
`SCHAR_MIN`
  `limits.h` (ISO): Range of Type.
`int sched_getaffinity (pid_t` pid`, size_t` cpusetsize`, cpu_set_t *`cpuset`)`
  `sched.h` (GNU): CPU Affinity.
`int sched_getparam (pid_t` pid`, struct sched_param *`param`)`
  `sched.h` (POSIX): Basic Scheduling Functions.
`int sched_get_priority_max (int` policy`)`
  `sched.h` (POSIX): Basic Scheduling Functions.
`int sched_get_priority_min (int` policy`)`
  `sched.h` (POSIX): Basic Scheduling Functions.
`int sched_getscheduler (pid_t` pid`)`
  `sched.h` (POSIX): Basic Scheduling Functions.
`int sched_rr_get_interval (pid_t` pid`, struct timespec *`interval`)`
  `sched.h` (POSIX): Basic Scheduling Functions.
`int sched_setaffinity (pid_t` pid`, size_t` cpusetsize`, const cpu_set_t *`cpuset`)`
  `sched.h` (GNU): CPU Affinity.
`int sched_setparam (pid_t` pid`, const struct sched_param *`param`)`
  `sched.h` (POSIX): Basic Scheduling Functions.
`int sched_setscheduler (pid_t` pid`, int` policy`, const struct sched_param *`param`)`
  `sched.h` (POSIX): Basic Scheduling Functions.
`int sched_yield (void)`
  `sched.h` (POSIX): Basic Scheduling Functions.
`_SC_INT_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_INT_MIN`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_JOB_CONTROL`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_LINE_MAX`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_LOGIN_NAME_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_LONG_BIT`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_MAPPED_FILES`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_MB_LEN_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_MEMLOCK`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_MEMLOCK_RANGE`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_MEMORY_PROTECTION`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_MESSAGE_PASSING`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_MQ_OPEN_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_MQ_PRIO_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_NGROUPS_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_NL_ARGMAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_NL_LANGMAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_NL_MSGMAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_NL_NMAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_NL_SETMAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_NL_TEXTMAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_NPROCESSORS_CONF`
  `unistd.h` (GNU): Constants for Sysconf.
`_SC_NPROCESSORS_ONLN`
  `unistd.h` (GNU): Constants for Sysconf.
`_SC_NZERO`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_OPEN_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_PAGESIZE`
  `unistd.h` (GNU): Constants for Sysconf.
`_SC_PHYS_PAGES`
  `unistd.h` (GNU): Constants for Sysconf.
`_SC_PII`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_INTERNET`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_INTERNET_DGRAM`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_INTERNET_STREAM`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_OSI`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_OSI_CLTS`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_OSI_COTS`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_OSI_M`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_SOCKET`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PII_XTI`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_PRIORITIZED_IO`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_PRIORITY_SCHEDULING`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_REALTIME_SIGNALS`
  `unistdh.h` (POSIX.1): Constants for Sysconf.
`_SC_RTSIG_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_SAVED_IDS`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_SCHAR_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_SCHAR_MIN`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_SELECT`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_SEMAPHORES`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_SEM_NSEMS_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_SEM_VALUE_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_SHARED_MEMORY_OBJECTS`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_SHRT_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_SHRT_MIN`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_SIGQUEUE_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`SC_SSIZE_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_STREAM_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_SYNCHRONIZED_IO`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_ATTR_STACKADDR`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_ATTR_STACKSIZE`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_DESTRUCTOR_ITERATIONS`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_KEYS_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_PRIO_INHERIT`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_PRIO_PROTECT`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_PRIORITY_SCHEDULING`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_PROCESS_SHARED`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREADS`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_SAFE_FUNCTIONS`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_STACK_MIN`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_THREAD_THREADS_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_TIMER_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_TIMERS`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_T_IOV_MAX`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_TTY_NAME_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_TZNAME_MAX`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_UCHAR_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_UINT_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_UIO_MAXIOV`
  `unistd.h` (POSIX.1g): Constants for Sysconf.
`_SC_ULONG_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_USHRT_MAX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_VERSION`
  `unistd.h` (POSIX.1): Constants for Sysconf.
`_SC_VERSION`
  `unistd.h` (POSIX.2): Constants for Sysconf.
`_SC_WORD_BIT`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_CRYPT`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_ENH_I18N`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_LEGACY`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_REALTIME`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_REALTIME_THREADS`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_SHM`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_UNIX`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_VERSION`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_XCU_VERSION`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_XPG2`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_XPG3`
  `unistd.h` (X/Open): Constants for Sysconf.
`_SC_XOPEN_XPG4`
  `unistd.h` (X/Open): Constants for Sysconf.
`char * secure_getenv (const char *`name`)`
  `stdlib.h` (GNU): Environment Access.
`unsigned short int * seed48 (unsigned short int` seed16v`[3])`
  `stdlib.h` (SVID): SVID Random.
`int seed48_r (unsigned short int` seed16v`[3], struct drand48_data *`buffer`)`
  `stdlib.h` (GNU): SVID Random.
`int SEEK_CUR`
  `stdio.h` (ISO): File Positioning.
`void seekdir (DIR *`dirstream`, long int` pos`)`
  `dirent.h` (BSD): Random Access Directory.
`int SEEK_END`
  `stdio.h` (ISO): File Positioning.
`int SEEK_SET`
  `stdio.h` (ISO): File Positioning.
`int select (int` nfds`, fd_set *`read-fds`, fd_set *`write-fds`, fd_set *`except-fds`, struct timeval *`timeout`)`
  `sys/types.h` (BSD): Waiting for I/O.
`ssize_t send (int` socket`, const void *`buffer`, size_t` size`, int` flags`)`
  `sys/socket.h` (BSD): Sending Data.
`ssize_t sendmsg (int` socket`, const struct msghdr *`message`, int` flags`)`
  `sys/socket.h` (BSD): Receiving Datagrams.
`ssize_t sendto (int` socket`, const void *`buffer`, size_t` size`, int` flags`, struct sockaddr *`addr`, socklen_t` length`)`
  `sys/socket.h` (BSD): Sending Datagrams.
`void setbuf (FILE *`stream`, char *`buf`)`
  `stdio.h` (ISO): Controlling Buffering.
`void setbuffer (FILE *`stream`, char *`buf`, size_t` size`)`
  `stdio.h` (BSD): Controlling Buffering.
`int setcontext (const ucontext_t *`ucp`)`
  `ucontext.h` (SVID): System V contexts.
`int setdomainname (const char *`name`, size_t` length`)`
  `unistd.h` (???): Host Identification.
`int setegid (gid_t` newgid`)`
  `unistd.h` (POSIX.1): Setting Groups.
`int setenv (const char *`name`, const char *`value`, int` replace`)`
  `stdlib.h` (BSD): Environment Access.
`int seteuid (uid_t` neweuid`)`
  `unistd.h` (POSIX.1): Setting User ID.
`int setfsent (void)`
  `fstab.h` (BSD): fstab.
`int setgid (gid_t` newgid`)`
  `unistd.h` (POSIX.1): Setting Groups.
`void setgrent (void)`
  `grp.h` (SVID, BSD): Scanning All Groups.
`int setgroups (size_t` count`, const gid_t *`groups`)`
  `grp.h` (BSD): Setting Groups.
`void sethostent (int` stayopen`)`
  `netdb.h` (BSD): Host Names.
`int sethostid (long int` id`)`
  `unistd.h` (BSD): Host Identification.
`int sethostname (const char *`name`, size_t` length`)`
  `unistd.h` (BSD): Host Identification.
`int setitimer (int` which`, const struct itimerval *`new`, struct itimerval *`old`)`
  `sys/time.h` (BSD): Setting an Alarm.
`int setjmp (jmp_buf` state`)`
  `setjmp.h` (ISO): Non-Local Details.
`void setkey (const char *`key`)`
  `crypt.h` (BSD, SVID): DES Encryption.
`void setkey_r (const char *`key`, struct crypt_data *` data`)`
  `crypt.h` (GNU): DES Encryption.
`void setlinebuf (FILE *`stream`)`
  `stdio.h` (BSD): Controlling Buffering.
`char * setlocale (int` category`, const char *`locale`)`
  `locale.h` (ISO): Setting the Locale.
`int setlogmask (int` mask`)`
  `syslog.h` (BSD): setlogmask.
`FILE * setmntent (const char *`file`, const char *`mode`)`
  `mntent.h` (BSD): mtab.
`void setnetent (int` stayopen`)`
  `netdb.h` (BSD): Networks Database.
`int setnetgrent (const char *`netgroup`)`
  `netdb.h` (BSD): Lookup Netgroup.
`int setpgid (pid_t` pid`, pid_t` pgid`)`
  `unistd.h` (POSIX.1): Process Group Functions.
`int setpgrp (pid_t` pid`, pid_t` pgid`)`
  `unistd.h` (BSD): Process Group Functions.
`int setpriority (int` class`, int` id`, int` niceval`)`
  `sys/resource.h` (BSD,POSIX): Traditional Scheduling Functions.
`void setprotoent (int` stayopen`)`
  `netdb.h` (BSD): Protocols Database.
`void setpwent (void)`
  `pwd.h` (SVID, BSD): Scanning All Users.
`int setregid (gid_t` rgid`, gid_t` egid`)`
  `unistd.h` (BSD): Setting Groups.
`int setreuid (uid_t` ruid`, uid_t` euid`)`
  `unistd.h` (BSD): Setting User ID.
`int setrlimit (int` resource`, const struct rlimit *`rlp`)`
  `sys/resource.h` (BSD): Limits on Resources.
`int setrlimit64 (int` resource`, const struct rlimit64 *`rlp`)`
  `sys/resource.h` (Unix98): Limits on Resources.
`void setservent (int` stayopen`)`
  `netdb.h` (BSD): Services Database.
`pid_t setsid (void)`
  `unistd.h` (POSIX.1): Process Group Functions.
`int setsockopt (int` socket`, int` level`, int` optname`, const void *`optval`, socklen_t` optlen`)`
  `sys/socket.h` (BSD): Socket Option Functions.
`char * setstate (char *`state`)`
  `stdlib.h` (BSD): BSD Random.
`int setstate_r (char *restrict` statebuf`, struct random_data *restrict` buf`)`
  `stdlib.h` (GNU): BSD Random.
`int settimeofday (const struct timeval *`tp`, const struct timezone *`tzp`)`
  `sys/time.h` (BSD): High-Resolution Calendar.
`int setuid (uid_t` newuid`)`
  `unistd.h` (POSIX.1): Setting User ID.
`void setutent (void)`
  `utmp.h` (SVID): Manipulating the Database.
`void setutxent (void)`
  `utmpx.h` (XPG4.2): XPG Functions.
`int setvbuf (FILE *`stream`, char *`buf`, int` mode`, size_t` size`)`
  `stdio.h` (ISO): Controlling Buffering.
`SHRT_MAX`
  `limits.h` (ISO): Range of Type.
`SHRT_MIN`
  `limits.h` (ISO): Range of Type.
`int shutdown (int` socket`, int` how`)`
  `sys/socket.h` (BSD): Closing a Socket.
`S_IEXEC`
  `sys/stat.h` (BSD): Permission Bits.
`S_IFBLK`
  `sys/stat.h` (BSD): Testing File Type.
`S_IFCHR`
  `sys/stat.h` (BSD): Testing File Type.
`S_IFDIR`
  `sys/stat.h` (BSD): Testing File Type.
`S_IFIFO`
  `sys/stat.h` (BSD): Testing File Type.
`S_IFLNK`
  `sys/stat.h` (BSD): Testing File Type.
`int S_IFMT`
  `sys/stat.h` (BSD): Testing File Type.
`S_IFREG`
  `sys/stat.h` (BSD): Testing File Type.
`S_IFSOCK`
  `sys/stat.h` (BSD): Testing File Type.
`int SIGABRT`
  `signal.h` (ISO): Program Error Signals.
`int sigaction (int` signum`, const struct sigaction *restrict` action`, struct sigaction *restrict` old-action`)`
  `signal.h` (POSIX.1): Advanced Signal Handling.
`int sigaddset (sigset_t *`set`, int` signum`)`
  `signal.h` (POSIX.1): Signal Sets.
`int SIGALRM`
  `signal.h` (POSIX.1): Alarm Signals.
`int sigaltstack (const stack_t *restrict` stack`, stack_t *restrict` oldstack`)`
  `signal.h` (XPG): Signal Stack.
`sig_atomic_t`
  `signal.h` (ISO): Atomic Types.
`SIG_BLOCK`
  `signal.h` (POSIX.1): Process Signal Mask.
`int sigblock (int` mask`)`
  `signal.h` (BSD): Blocking in BSD.
`int SIGBUS`
  `signal.h` (BSD): Program Error Signals.
`int SIGCHLD`
  `signal.h` (POSIX.1): Job Control Signals.
`int SIGCLD`
  `signal.h` (SVID): Job Control Signals.
`int SIGCONT`
  `signal.h` (POSIX.1): Job Control Signals.
`int sigdelset (sigset_t *`set`, int` signum`)`
  `signal.h` (POSIX.1): Signal Sets.
`int sigemptyset (sigset_t *`set`)`
  `signal.h` (POSIX.1): Signal Sets.
`int SIGEMT`
  `signal.h` (BSD): Program Error Signals.
`sighandler_t SIG_ERR`
  `signal.h` (ISO): Basic Signal Handling.
`int sigfillset (sigset_t *`set`)`
  `signal.h` (POSIX.1): Signal Sets.
`int SIGFPE`
  `signal.h` (ISO): Program Error Signals.
`sighandler_t`
  `signal.h` (GNU): Basic Signal Handling.
`int SIGHUP`
  `signal.h` (POSIX.1): Termination Signals.
`int SIGILL`
  `signal.h` (ISO): Program Error Signals.
`int SIGINFO`
  `signal.h` (BSD): Miscellaneous Signals.
`int SIGINT`
  `signal.h` (ISO): Termination Signals.
`int siginterrupt (int` signum`, int` failflag`)`
  `signal.h` (BSD): BSD Handler.
`int SIGIO`
  `signal.h` (BSD): Asynchronous I/O Signals.
`int SIGIOT`
  `signal.h` (Unix): Program Error Signals.
`int sigismember (const sigset_t *`set`, int` signum`)`
  `signal.h` (POSIX.1): Signal Sets.
`sigjmp_buf`
  `setjmp.h` (POSIX.1): Non-Local Exits and Signals.
`int SIGKILL`
  `signal.h` (POSIX.1): Termination Signals.
`void siglongjmp (sigjmp_buf` state`, int` value`)`
  `setjmp.h` (POSIX.1): Non-Local Exits and Signals.
`int SIGLOST`
  `signal.h` (GNU): Operation Error Signals.
`int sigmask (int` signum`)`
  `signal.h` (BSD): Blocking in BSD.
`sighandler_t signal (int` signum`, sighandler_t` action`)`
  `signal.h` (ISO): Basic Signal Handling.
`int signbit (`float-type x`)`
  `math.h` (ISO): FP Bit Twiddling.
`double significand (double` x`)`
  `math.h` (BSD): Normalization Functions.
`float significandf (float` x`)`
  `math.h` (BSD): Normalization Functions.
`long double significandl (long double` x`)`
  `math.h` (BSD): Normalization Functions.
`int sigpause (int` mask`)`
  `signal.h` (BSD): Blocking in BSD.
`int sigpending (sigset_t *`set`)`
  `signal.h` (POSIX.1): Checking for Pending Signals.
`int SIGPIPE`
  `signal.h` (POSIX.1): Operation Error Signals.
`int SIGPOLL`
  `signal.h` (SVID): Asynchronous I/O Signals.
`int sigprocmask (int` how`, const sigset_t *restrict` set`, sigset_t *restrict` oldset`)`
  `signal.h` (POSIX.1): Process Signal Mask.
`int SIGPROF`
  `signal.h` (BSD): Alarm Signals.
`int SIGQUIT`
  `signal.h` (POSIX.1): Termination Signals.
`int SIGSEGV`
  `signal.h` (ISO): Program Error Signals.
`int sigsetjmp (sigjmp_buf` state`, int` savesigs`)`
  `setjmp.h` (POSIX.1): Non-Local Exits and Signals.
`SIG_SETMASK`
  `signal.h` (POSIX.1): Process Signal Mask.
`int sigsetmask (int` mask`)`
  `signal.h` (BSD): Blocking in BSD.
`sigset_t`
  `signal.h` (POSIX.1): Signal Sets.
`int sigstack (struct sigstack *`stack`, struct sigstack *`oldstack`)`
  `signal.h` (BSD): Signal Stack.
`int SIGSTOP`
  `signal.h` (POSIX.1): Job Control Signals.
`int sigsuspend (const sigset_t *`set`)`
  `signal.h` (POSIX.1): Sigsuspend.
`int SIGSYS`
  `signal.h` (Unix): Program Error Signals.
`int SIGTERM`
  `signal.h` (ISO): Termination Signals.
`int SIGTRAP`
  `signal.h` (BSD): Program Error Signals.
`int SIGTSTP`
  `signal.h` (POSIX.1): Job Control Signals.
`int SIGTTIN`
  `signal.h` (POSIX.1): Job Control Signals.
`int SIGTTOU`
  `signal.h` (POSIX.1): Job Control Signals.
`SIG_UNBLOCK`
  `signal.h` (POSIX.1): Process Signal Mask.
`int SIGURG`
  `signal.h` (BSD): Asynchronous I/O Signals.
`int SIGUSR1`
  `signal.h` (POSIX.1): Miscellaneous Signals.
`int SIGUSR2`
  `signal.h` (POSIX.1): Miscellaneous Signals.
`int sigvec (int` signum`, const struct sigvec *`action`, struct sigvec *`old-action`)`
  `signal.h` (BSD): BSD Handler.
`int SIGVTALRM`
  `signal.h` (BSD): Alarm Signals.
`int SIGWINCH`
  `signal.h` (BSD): Miscellaneous Signals.
`int SIGXCPU`
  `signal.h` (BSD): Operation Error Signals.
`int SIGXFSZ`
  `signal.h` (BSD): Operation Error Signals.
`double sin (double` x`)`
  `math.h` (ISO): Trig Functions.
`void sincos (double` x`, double *`sinx`, double *`cosx`)`
  `math.h` (GNU): Trig Functions.
`void sincosf (float` x`, float *`sinx`, float *`cosx`)`
  `math.h` (GNU): Trig Functions.
`void sincosl (long double` x`, long double *`sinx`, long double *`cosx`)`
  `math.h` (GNU): Trig Functions.
`float sinf (float` x`)`
  `math.h` (ISO): Trig Functions.
`double sinh (double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`float sinhf (float` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double sinhl (long double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double sinl (long double` x`)`
  `math.h` (ISO): Trig Functions.
`S_IREAD`
  `sys/stat.h` (BSD): Permission Bits.
`S_IRGRP`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IROTH`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IRUSR`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IRWXG`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IRWXO`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IRWXU`
  `sys/stat.h` (POSIX.1): Permission Bits.
`int S_ISBLK (mode_t` m`)`
  `sys/stat.h` (POSIX): Testing File Type.
`int S_ISCHR (mode_t` m`)`
  `sys/stat.h` (POSIX): Testing File Type.
`int S_ISDIR (mode_t` m`)`
  `sys/stat.h` (POSIX): Testing File Type.
`int S_ISFIFO (mode_t` m`)`
  `sys/stat.h` (POSIX): Testing File Type.
`S_ISGID`
  `sys/stat.h` (POSIX): Permission Bits.
`int S_ISLNK (mode_t` m`)`
  `sys/stat.h` (GNU): Testing File Type.
`int S_ISREG (mode_t` m`)`
  `sys/stat.h` (POSIX): Testing File Type.
`int S_ISSOCK (mode_t` m`)`
  `sys/stat.h` (GNU): Testing File Type.
`S_ISUID`
  `sys/stat.h` (POSIX): Permission Bits.
`S_ISVTX`
  `sys/stat.h` (BSD): Permission Bits.
`S_IWGRP`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IWOTH`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IWRITE`
  `sys/stat.h` (BSD): Permission Bits.
`S_IWUSR`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IXGRP`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IXOTH`
  `sys/stat.h` (POSIX.1): Permission Bits.
`S_IXUSR`
  `sys/stat.h` (POSIX.1): Permission Bits.
`size_t`
  `stddef.h` (ISO): Important Data Types.
`unsigned int sleep (unsigned int` seconds`)`
  `unistd.h` (POSIX.1): Sleeping.
`int snprintf (char *`s`, size_t` size`, const char *`template`, ...)`
  `stdio.h` (GNU): Formatted Output Functions.
`SO_BROADCAST`
  `sys/socket.h` (BSD): Socket-Level Options.
`int SOCK_DGRAM`
  `sys/socket.h` (BSD): Communication Styles.
`int socket (int` namespace`, int` style`, int` protocol`)`
  `sys/socket.h` (BSD): Creating a Socket.
`int socketpair (int` namespace`, int` style`, int` protocol`, int` filedes`[2]``)`
  `sys/socket.h` (BSD): Socket Pairs.
`int SOCK_RAW`
  `sys/socket.h` (BSD): Communication Styles.
`int SOCK_RDM`
  `sys/socket.h` (BSD): Communication Styles.
`int SOCK_SEQPACKET`
  `sys/socket.h` (BSD): Communication Styles.
`int SOCK_STREAM`
  `sys/socket.h` (BSD): Communication Styles.
`SO_DEBUG`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_DONTROUTE`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_ERROR`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_KEEPALIVE`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_LINGER`
  `sys/socket.h` (BSD): Socket-Level Options.
`int SOL_SOCKET`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_OOBINLINE`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_RCVBUF`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_REUSEADDR`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_SNDBUF`
  `sys/socket.h` (BSD): Socket-Level Options.
`SO_STYLE`
  `sys/socket.h` (GNU): Socket-Level Options.
`SO_TYPE`
  `sys/socket.h` (BSD): Socket-Level Options.
`speed_t`
  `termios.h` (POSIX.1): Line Speed.
`int sprintf (char *`s`, const char *`template`, ...)`
  `stdio.h` (ISO): Formatted Output Functions.
`double sqrt (double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`float sqrtf (float` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`long double sqrtl (long double` x`)`
  `math.h` (ISO): Exponents and Logarithms.
`void srand (unsigned int` seed`)`
  `stdlib.h` (ISO): ISO Random.
`void srand48 (long int` seedval`)`
  `stdlib.h` (SVID): SVID Random.
`int srand48_r (long int` seedval`, struct drand48_data *`buffer`)`
  `stdlib.h` (GNU): SVID Random.
`void srandom (unsigned int` seed`)`
  `stdlib.h` (BSD): BSD Random.
`int srandom_r (unsigned int` seed`, struct random_data *`buf`)`
  `stdlib.h` (GNU): BSD Random.
`int sscanf (const char *`s`, const char *`template`, ...)`
  `stdio.h` (ISO): Formatted Input Functions.
`sighandler_t ssignal (int` signum`, sighandler_t` action`)`
  `signal.h` (SVID): Basic Signal Handling.
`ssize_t SSIZE_MAX`
  `limits.h` (POSIX.1): General Limits.
`ssize_t`
  `unistd.h` (POSIX.1): I/O Primitives.
`stack_t`
  `signal.h` (XPG): Signal Stack.
`int stat (const char *`filename`, struct stat *`buf`)`
  `sys/stat.h` (POSIX.1): Reading Attributes.
`int stat64 (const char *`filename`, struct stat64 *`buf`)`
  `sys/stat.h` (Unix98): Reading Attributes.
`FILE * stderr`
  `stdio.h` (ISO): Standard Streams.
`STDERR_FILENO`
  `unistd.h` (POSIX.1): Descriptors and Streams.
`FILE * stdin`
  `stdio.h` (ISO): Standard Streams.
`STDIN_FILENO`
  `unistd.h` (POSIX.1): Descriptors and Streams.
`FILE * stdout`
  `stdio.h` (ISO): Standard Streams.
`STDOUT_FILENO`
  `unistd.h` (POSIX.1): Descriptors and Streams.
`int stime (const time_t *`newtime`)`
  `time.h` (SVID, XPG): Simple Calendar Time.
`char * stpcpy (char *restrict` to`, const char *restrict` from`)`
  `string.h` (Unknown origin): Copying and Concatenation.
`char * stpncpy (char *restrict` to`, const char *restrict` from`, size_t` size`)`
  `string.h` (GNU): Copying and Concatenation.
`int strcasecmp (const char *`s1`, const char *`s2`)`
  `string.h` (BSD): String/Array Comparison.
`char * strcasestr (const char *`haystack`, const char *`needle`)`
  `string.h` (GNU): Search Functions.
`char * strcat (char *restrict` to`, const char *restrict` from`)`
  `string.h` (ISO): Copying and Concatenation.
`char * strchr (const char *`string`, int` c`)`
  `string.h` (ISO): Search Functions.
`char * strchrnul (const char *`string`, int` c`)`
  `string.h` (GNU): Search Functions.
`int strcmp (const char *`s1`, const char *`s2`)`
  `string.h` (ISO): String/Array Comparison.
`int strcoll (const char *`s1`, const char *`s2`)`
  `string.h` (ISO): Collation Functions.
`char * strcpy (char *restrict` to`, const char *restrict` from`)`
  `string.h` (ISO): Copying and Concatenation.
`size_t strcspn (const char *`string`, const char *`stopset`)`
  `string.h` (ISO): Search Functions.
`char * strdup (const char *`s`)`
  `string.h` (SVID): Copying and Concatenation.
`char * strdupa (const char *`s`)`
  `string.h` (GNU): Copying and Concatenation.
`int STREAM_MAX`
  `limits.h` (POSIX.1): General Limits.
`char * strerror (int` errnum`)`
  `string.h` (ISO): Error Messages.
`char * strerror_r (int` errnum`, char *`buf`, size_t` n`)`
  `string.h` (GNU): Error Messages.
`char * strfry (char *`string`)`
  `string.h` (GNU): strfry.
`size_t strftime (char *`s`, size_t` size`, const char *`template`, const struct tm *`brokentime`)`
  `time.h` (ISO): Formatting Calendar Time.
`size_t strlen (const char *`s`)`
  `string.h` (ISO): String Length.
`int strncasecmp (const char *`s1`, const char *`s2`, size_t` n`)`
  `string.h` (BSD): String/Array Comparison.
`char * strncat (char *restrict` to`, const char *restrict` from`, size_t` size`)`
  `string.h` (ISO): Copying and Concatenation.
`int strncmp (const char *`s1`, const char *`s2`, size_t` size`)`
  `string.h` (ISO): String/Array Comparison.
`char * strncpy (char *restrict` to`, const char *restrict` from`, size_t` size`)`
  `string.h` (ISO): Copying and Concatenation.
`char * strndup (const char *`s`, size_t` size`)`
  `string.h` (GNU): Copying and Concatenation.
`char * strndupa (const char *`s`, size_t` size`)`
  `string.h` (GNU): Copying and Concatenation.
`size_t strnlen (const char *`s`, size_t` maxlen`)`
  `string.h` (GNU): String Length.
`char * strpbrk (const char *`string`, const char *`stopset`)`
  `string.h` (ISO): Search Functions.
`char * strptime (const char *`s`, const char *`fmt`, struct tm *`tp`)`
  `time.h` (XPG4): Low-Level Time String Parsing.
`char * strrchr (const char *`string`, int` c`)`
  `string.h` (ISO): Search Functions.
`char * strsep (char **`string_ptr`, const char *`delimiter`)`
  `string.h` (BSD): Finding Tokens in a String.
`char * strsignal (int` signum`)`
  `string.h` (GNU): Signal Messages.
`size_t strspn (const char *`string`, const char *`skipset`)`
  `string.h` (ISO): Search Functions.
`char * strstr (const char *`haystack`, const char *`needle`)`
  `string.h` (ISO): Search Functions.
`double strtod (const char *restrict` string`, char **restrict` tailptr`)`
  `stdlib.h` (ISO): Parsing of Floats.
`float strtof (const char *`string`, char **`tailptr`)`
  `stdlib.h` (ISO): Parsing of Floats.
`intmax_t strtoimax (const char *restrict` string`, char **restrict` tailptr`, int` base`)`
  `inttypes.h` (ISO): Parsing of Integers.
`char * strtok (char *restrict` newstring`, const char *restrict` delimiters`)`
  `string.h` (ISO): Finding Tokens in a String.
`char * strtok_r (char *`newstring`, const char *`delimiters`, char **`save_ptr`)`
  `string.h` (POSIX): Finding Tokens in a String.
`long int strtol (const char *restrict` string`, char **restrict` tailptr`, int` base`)`
  `stdlib.h` (ISO): Parsing of Integers.
`long double strtold (const char *`string`, char **`tailptr`)`
  `stdlib.h` (ISO): Parsing of Floats.
`long long int strtoll (const char *restrict` string`, char **restrict` tailptr`, int` base`)`
  `stdlib.h` (ISO): Parsing of Integers.
`long long int strtoq (const char *restrict` string`, char **restrict` tailptr`, int` base`)`
  `stdlib.h` (BSD): Parsing of Integers.
`unsigned long int strtoul (const char *retrict` string`, char **restrict` tailptr`, int` base`)`
  `stdlib.h` (ISO): Parsing of Integers.
`unsigned long long int strtoull (const char *restrict` string`, char **restrict` tailptr`, int` base`)`
  `stdlib.h` (ISO): Parsing of Integers.
`uintmax_t strtoumax (const char *restrict` string`, char **restrict` tailptr`, int` base`)`
  `inttypes.h` (ISO): Parsing of Integers.
`unsigned long long int strtouq (const char *restrict` string`, char **restrict` tailptr`, int` base`)`
  `stdlib.h` (BSD): Parsing of Integers.
`struct aiocb`
  `aio.h` (POSIX.1b): Asynchronous I/O.
`struct aiocb64`
  `aio.h` (POSIX.1b): Asynchronous I/O.
`struct aioinit`
  `aio.h` (GNU): Configuration of AIO.
`struct argp`
  `argp.h` (GNU): Argp Parsers.
`struct argp_child`
  `argp.h` (GNU): Argp Children.
`struct argp_option`
  `argp.h` (GNU): Argp Option Vectors.
`struct argp_state`
  `argp.h` (GNU): Argp Parsing State.
`struct dirent`
  `dirent.h` (POSIX.1): Directory Entries.
`struct exit_status`
  `utmp.h` (SVID): Manipulating the Database.
`struct flock`
  `fcntl.h` (POSIX.1): File Locks.
`struct fstab`
  `fstab.h` (BSD): fstab.
`struct FTW`
  `ftw.h` (XPG4.2): Working with Directory Trees.
`struct __gconv_step`
  `gconv.h` (GNU): glibc iconv Implementation.
`struct __gconv_step_data`
  `gconv.h` (GNU): glibc iconv Implementation.
`struct group`
  `grp.h` (POSIX.1): Group Data Structure.
`struct hostent`
  `netdb.h` (BSD): Host Names.
`struct if_nameindex`
  `net/if.h` (IPv6 basic API): Interface Naming.
`struct in6_addr`
  `netinet/in.h` (IPv6 basic API): Host Address Data Type.
`struct in_addr`
  `netinet/in.h` (BSD): Host Address Data Type.
`struct iovec`
  `sys/uio.h` (BSD): Scatter-Gather.
`struct itimerval`
  `sys/time.h` (BSD): Setting an Alarm.
`struct lconv`
  `locale.h` (ISO): The Lame Way to Locale Data.
`struct linger`
  `sys/socket.h` (BSD): Socket-Level Options.
`struct mallinfo`
  `malloc.h` (GNU): Statistics of Malloc.
`struct mntent`
  `mntent.h` (BSD): mtab.
`struct msghdr`
  `sys/socket.h` (BSD): Receiving Datagrams.
`struct netent`
  `netdb.h` (BSD): Networks Database.
`struct obstack`
  `obstack.h` (GNU): Creating Obstacks.
`struct option`
  `getopt.h` (GNU): Getopt Long Options.
`struct passwd`
  `pwd.h` (POSIX.1): User Data Structure.
`struct printf_info`
  `printf.h` (GNU): Conversion Specifier Options.
`struct protoent`
  `netdb.h` (BSD): Protocols Database.
`struct random_data`
  `stdlib.h` (GNU): BSD Random.
`struct rlimit`
  `sys/resource.h` (BSD): Limits on Resources.
`struct rlimit64`
  `sys/resource.h` (Unix98): Limits on Resources.
`struct rusage`
  `sys/resource.h` (BSD): Resource Usage.
`struct sched_param`
  `sched.h` (POSIX): Basic Scheduling Functions.
`struct servent`
  `netdb.h` (BSD): Services Database.
`struct sgttyb`
  `termios.h` (BSD): BSD Terminal Modes.
`struct sigaction`
  `signal.h` (POSIX.1): Advanced Signal Handling.
`struct sigstack`
  `signal.h` (BSD): Signal Stack.
`struct sigvec`
  `signal.h` (BSD): BSD Handler.
`struct sockaddr`
  `sys/socket.h` (BSD): Address Formats.
`struct sockaddr_in`
  `netinet/in.h` (BSD): Internet Address Formats.
`struct sockaddr_un`
  `sys/un.h` (BSD): Local Namespace Details.
`struct stat`
  `sys/stat.h` (POSIX.1): Attribute Meanings.
`struct stat64`
  `sys/stat.h` (LFS): Attribute Meanings.
`struct termios`
  `termios.h` (POSIX.1): Mode Data Types.
`struct timespec`
  `sys/time.h` (POSIX.1): Elapsed Time.
`struct timeval`
  `sys/time.h` (BSD): Elapsed Time.
`struct timezone`
  `sys/time.h` (BSD): High-Resolution Calendar.
`struct tm`
  `time.h` (ISO): Broken-down Time.
`struct tms`
  `sys/times.h` (POSIX.1): Processor Time.
`struct utimbuf`
  `utime.h` (POSIX.1): File Times.
`struct utsname`
  `sys/utsname.h` (POSIX.1): Platform Type.
`int strverscmp (const char *`s1`, const char *`s2`)`
  `string.h` (GNU): String/Array Comparison.
`size_t strxfrm (char *restrict` to`, const char *restrict` from`, size_t` size`)`
  `string.h` (ISO): Collation Functions.
`int stty (int` filedes`, const struct sgttyb *`attributes`)`
  `sgtty.h` (BSD): BSD Terminal Modes.
`int S_TYPEISMQ (struct stat *`s`)`
  `sys/stat.h` (POSIX): Testing File Type.
`int S_TYPEISSEM (struct stat *`s`)`
  `sys/stat.h` (POSIX): Testing File Type.
`int S_TYPEISSHM (struct stat *`s`)`
  `sys/stat.h` (POSIX): Testing File Type.
`int SUN_LEN (`struct sockaddr_un * ptr`)`
  `sys/un.h` (BSD): Local Namespace Details.
`_SVID_SOURCE`
  (GNU): Feature Test Macros.
`int SV_INTERRUPT`
  `signal.h` (BSD): BSD Handler.
`int SV_ONSTACK`
  `signal.h` (BSD): BSD Handler.
`int SV_RESETHAND`
  `signal.h` (Sun): BSD Handler.
`int swapcontext (ucontext_t *restrict` oucp`, const ucontext_t *restrict` ucp`)`
  `ucontext.h` (SVID): System V contexts.
`int swprintf (wchar_t *`s`, size_t` size`, const wchar_t *`template`, ...)`
  `wchar.h` (GNU): Formatted Output Functions.
`int swscanf (const wchar_t *`ws`, const wchar_t *`template`, ...)`
  `wchar.h` (ISO): Formatted Input Functions.
`int symlink (const char *`oldname`, const char *`newname`)`
  `unistd.h` (BSD): Symbolic Links.
`SYMLINK_MAX`
  `limits.h` (POSIX.1): File Minimums.
`void sync (void)`
  `unistd.h` (X/Open): Synchronizing I/O.
`long int syscall (long int` sysno`, ...)`
  `unistd.h` (???): System Calls.
`long int sysconf (int` parameter`)`
  `unistd.h` (POSIX.1): Sysconf Definition.
`int sysctl (int *`names`, int` nlen`, void *`oldval`, size_t *`oldlenp`, void *`newval`, size_t` newlen`)`
  `sys/sysctl.h` (BSD): System Parameters.
`void syslog (int` facility_priority`, const char *`format`, ...)`
  `syslog.h` (BSD): syslog; vsyslog.
`int system (const char *`command`)`
  `stdlib.h` (ISO): Running a Command.
`sighandler_t sysv_signal (int` signum`, sighandler_t` action`)`
  `signal.h` (GNU): Basic Signal Handling.
`double tan (double` x`)`
  `math.h` (ISO): Trig Functions.
`float tanf (float` x`)`
  `math.h` (ISO): Trig Functions.
`double tanh (double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`float tanhf (float` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double tanhl (long double` x`)`
  `math.h` (ISO): Hyperbolic Functions.
`long double tanl (long double` x`)`
  `math.h` (ISO): Trig Functions.
`int tcdrain (int` filedes`)`
  `termios.h` (POSIX.1): Line Control.
`tcflag_t`
  `termios.h` (POSIX.1): Mode Data Types.
`int tcflow (int` filedes`, int` action`)`
  `termios.h` (POSIX.1): Line Control.
`int tcflush (int` filedes`, int` queue`)`
  `termios.h` (POSIX.1): Line Control.
`int tcgetattr (int` filedes`, struct termios *`termios-p`)`
  `termios.h` (POSIX.1): Mode Functions.
`pid_t tcgetpgrp (int` filedes`)`
  `unistd.h` (POSIX.1): Terminal Access Functions.
`pid_t tcgetsid (int` fildes`)`
  `termios.h` (Unix98): Terminal Access Functions.
`TCSADRAIN`
  `termios.h` (POSIX.1): Mode Functions.
`TCSAFLUSH`
  `termios.h` (POSIX.1): Mode Functions.
`TCSANOW`
  `termios.h` (POSIX.1): Mode Functions.
`TCSASOFT`
  `termios.h` (BSD): Mode Functions.
`int tcsendbreak (int` filedes`, int` duration`)`
  `termios.h` (POSIX.1): Line Control.
`int tcsetattr (int` filedes`, int` when`, const struct termios *`termios-p`)`
  `termios.h` (POSIX.1): Mode Functions.
`int tcsetpgrp (int` filedes`, pid_t` pgid`)`
  `unistd.h` (POSIX.1): Terminal Access Functions.
`void * tdelete (const void *`key`, void **`rootp`, comparison_fn_t` compar`)`
  `search.h` (SVID): Tree Search Function.
`void tdestroy (void *`vroot`, __free_fn_t` freefct`)`
  `search.h` (GNU): Tree Search Function.
`long int telldir (DIR *`dirstream`)`
  `dirent.h` (BSD): Random Access Directory.
`TEMP_FAILURE_RETRY (`expression`)`
  `unistd.h` (GNU): Interrupted Primitives.
`char * tempnam (const char *`dir`, const char *`prefix`)`
  `stdio.h` (SVID): Temporary Files.
`char * textdomain (const char *`domainname`)`
  `libintl.h` (GNU): Locating gettext catalog.
`void * tfind (const void *`key`, void *const *`rootp`, comparison_fn_t` compar`)`
  `search.h` (SVID): Tree Search Function.
`double tgamma (double` x`)`
  `math.h` (XPG, ISO): Special Functions.
`float tgammaf (float` x`)`
  `math.h` (XPG, ISO): Special Functions.
`long double tgammal (long double` x`)`
  `math.h` (XPG, ISO): Special Functions.
`time_t time (time_t *`result`)`
  `time.h` (ISO): Simple Calendar Time.
`time_t timegm (struct tm *`brokentime`)`
  `time.h` (???): Broken-down Time.
`time_t timelocal (struct tm *`brokentime`)`
  `time.h` (???): Broken-down Time.
`clock_t times (struct tms *`buffer`)`
  `sys/times.h` (POSIX.1): Processor Time.
`time_t`
  `time.h` (ISO): Simple Calendar Time.
`long int timezone`
  `time.h` (SVID): Time Zone Functions.
`FILE * tmpfile (void)`
  `stdio.h` (ISO): Temporary Files.
`FILE * tmpfile64 (void)`
  `stdio.h` (Unix98): Temporary Files.
`int TMP_MAX`
  `stdio.h` (ISO): Temporary Files.
`char * tmpnam (char *`result`)`
  `stdio.h` (ISO): Temporary Files.
`char * tmpnam_r (char *`result`)`
  `stdio.h` (GNU): Temporary Files.
`int toascii (int` c`)`
  `ctype.h` (SVID, BSD): Case Conversion.
`int _tolower (int` c`)`
  `ctype.h` (SVID): Case Conversion.
`int tolower (int` c`)`
  `ctype.h` (ISO): Case Conversion.
`tcflag_t TOSTOP`
  `termios.h` (POSIX.1): Local Modes.
`int _toupper (int` c`)`
  `ctype.h` (SVID): Case Conversion.
`int toupper (int` c`)`
  `ctype.h` (ISO): Case Conversion.
`wint_t towctrans (wint_t` wc`, wctrans_t` desc`)`
  `wctype.h` (ISO): Wide Character Case Conversion.
`wint_t towlower (wint_t` wc`)`
  `wctype.h` (ISO): Wide Character Case Conversion.
`wint_t towupper (wint_t` wc`)`
  `wctype.h` (ISO): Wide Character Case Conversion.
`double trunc (double` x`)`
  `math.h` (ISO): Rounding Functions.
`int truncate (const char *`filename`, off_t` length`)`
  `unistd.h` (X/Open): File Size.
`int truncate64 (const char *`name`, off64_t` length`)`
  `unistd.h` (Unix98): File Size.
`float truncf (float` x`)`
  `math.h` (ISO): Rounding Functions.
`long double truncl (long double` x`)`
  `math.h` (ISO): Rounding Functions.
`TRY_AGAIN`
  `netdb.h` (BSD): Host Names.
`void * tsearch (const void *`key`, void **`rootp`, comparison_fn_t` compar`)`
  `search.h` (SVID): Tree Search Function.
`char * ttyname (int` filedes`)`
  `unistd.h` (POSIX.1): Is It a Terminal.
`int ttyname_r (int` filedes`, char *`buf`, size_t` len`)`
  `unistd.h` (POSIX.1): Is It a Terminal.
`void twalk (const void *`root`, __action_fn_t` action`)`
  `search.h` (SVID): Tree Search Function.
`char * tzname [2]`
  `time.h` (POSIX.1): Time Zone Functions.
`int TZNAME_MAX`
  `limits.h` (POSIX.1): General Limits.
`void tzset (void)`
  `time.h` (POSIX.1): Time Zone Functions.
`UCHAR_MAX`
  `limits.h` (ISO): Range of Type.
`ucontext_t`
  `ucontext.h` (SVID): System V contexts.
`uid_t`
  `sys/types.h` (POSIX.1): Reading Persona.
`UINT_MAX`
  `limits.h` (ISO): Range of Type.
`long int ulimit (int` cmd`, ...)`
  `ulimit.h` (BSD): Limits on Resources.
`ULLONG_MAX`
  `limits.h` (ISO): Range of Type.
`ULONG_LONG_MAX`
  `limits.h` (GNU): Range of Type.
`ULONG_MAX`
  `limits.h` (ISO): Range of Type.
`mode_t umask (mode_t` mask`)`
  `sys/stat.h` (POSIX.1): Setting Permissions.
`int umount (const char *`file`)`
  `sys/mount.h` (SVID, GNU): Mount-Unmount-Remount.
`int umount2 (const char *`file`, int` flags`)`
  `sys/mount.h` (GNU): Mount-Unmount-Remount.
`int uname (struct utsname *`info`)`
  `sys/utsname.h` (POSIX.1): Platform Type.
`int ungetc (int` c`, FILE *`stream`)`
  `stdio.h` (ISO): How Unread.
`wint_t ungetwc (wint_t` wc`, FILE *`stream`)`
  `wchar.h` (ISO): How Unread.
`union wait`
  `sys/wait.h` (BSD): BSD Wait Functions.
`int unlink (const char *`filename`)`
  `unistd.h` (POSIX.1): Deleting Files.
`int unlockpt (int` filedes`)`
  `stdlib.h` (SVID, XPG4.2): Allocation.
`int unsetenv (const char *`name`)`
  `stdlib.h` (BSD): Environment Access.
`void updwtmp (const char *`wtmp_file`, const struct utmp *`utmp`)`
  `utmp.h` (SVID): Manipulating the Database.
`USER_PROCESS`
  `utmp.h` (SVID): Manipulating the Database.
`USER_PROCESS`
  `utmpx.h` (XPG4.2): XPG Functions.
`USHRT_MAX`
  `limits.h` (ISO): Range of Type.
`int utime (const char *`filename`, const struct utimbuf *`times`)`
  `utime.h` (POSIX.1): File Times.
`int utimes (const char *`filename`, const struct timeval` tvp`[2]``)`
  `sys/time.h` (BSD): File Times.
`int utmpname (const char *`file`)`
  `utmp.h` (SVID): Manipulating the Database.
`int utmpxname (const char *`file`)`
  `utmpx.h` (XPG4.2): XPG Functions.
type `va_arg (va_list` ap`,` type`)`
  `stdarg.h` (ISO): Argument Macros.
`void va_copy (va_list` dest`, va_list` src`)`
  `stdarg.h` (ISO): Argument Macros.
`void va_end (va_list` ap`)`
  `stdarg.h` (ISO): Argument Macros.
`va_list`
  `stdarg.h` (ISO): Argument Macros.
`void * valloc (size_t` size`)`
  `malloc.h`, `stdlib.h` (BSD): Aligned Memory Blocks.
`int vasprintf (char **`ptr`, const char *`template`, va_list` ap`)`
  `stdio.h` (GNU): Variable Arguments Output.
`void va_start (va_list` ap`,` last-required`)`
  `stdarg.h` (ISO): Argument Macros.
`int VDISCARD`
  `termios.h` (BSD): Other Special.
`int VDSUSP`
  `termios.h` (BSD): Signal Characters.
`int VEOF`
  `termios.h` (POSIX.1): Editing Characters.
`int VEOL`
  `termios.h` (POSIX.1): Editing Characters.
`int VEOL2`
  `termios.h` (BSD): Editing Characters.
`int VERASE`
  `termios.h` (POSIX.1): Editing Characters.
`void verr (int` status`, const char *`format`, va_list` ap`)`
  `err.h` (BSD): Error Messages.
`void verrx (int` status`, const char *`format`, va_list` ap`)`
  `err.h` (BSD): Error Messages.
`int versionsort (const void *`a`, const void *`b`)`
  `dirent.h` (GNU): Scanning Directory Content.
`int versionsort64 (const void *`a`, const void *`b`)`
  `dirent.h` (GNU): Scanning Directory Content.
`pid_t vfork (void)`
  `unistd.h` (BSD): Creating a Process.
`int vfprintf (FILE *`stream`, const char *`template`, va_list` ap`)`
  `stdio.h` (ISO): Variable Arguments Output.
`int vfscanf (FILE *`stream`, const char *`template`, va_list` ap`)`
  `stdio.h` (ISO): Variable Arguments Input.
`int vfwprintf (FILE *`stream`, const wchar_t *`template`, va_list` ap`)`
  `wchar.h` (ISO): Variable Arguments Output.
`int vfwscanf (FILE *`stream`, const wchar_t *`template`, va_list` ap`)`
  `wchar.h` (ISO): Variable Arguments Input.
`int VINTR`
  `termios.h` (POSIX.1): Signal Characters.
`int VKILL`
  `termios.h` (POSIX.1): Editing Characters.
`int vlimit (int` resource`, int` limit`)`
  `sys/vlimit.h` (BSD): Limits on Resources.
`int VLNEXT`
  `termios.h` (BSD): Other Special.
`int VMIN`
  `termios.h` (POSIX.1): Noncanonical Input.
`void (*error_print_progname) (void)`
  `error.h` (GNU): Error Messages.
`int vprintf (const char *`template`, va_list` ap`)`
  `stdio.h` (ISO): Variable Arguments Output.
`int VQUIT`
  `termios.h` (POSIX.1): Signal Characters.
`int VREPRINT`
  `termios.h` (BSD): Editing Characters.
`int vscanf (const char *`template`, va_list` ap`)`
  `stdio.h` (ISO): Variable Arguments Input.
`int vsnprintf (char *`s`, size_t` size`, const char *`template`, va_list` ap`)`
  `stdio.h` (GNU): Variable Arguments Output.
`int vsprintf (char *`s`, const char *`template`, va_list` ap`)`
  `stdio.h` (ISO): Variable Arguments Output.
`int vsscanf (const char *`s`, const char *`template`, va_list` ap`)`
  `stdio.h` (ISO): Variable Arguments Input.
`int VSTART`
  `termios.h` (POSIX.1): Start/Stop Characters.
`int VSTATUS`
  `termios.h` (BSD): Other Special.
`int VSTOP`
  `termios.h` (POSIX.1): Start/Stop Characters.
`int VSUSP`
  `termios.h` (POSIX.1): Signal Characters.
`int vswprintf (wchar_t *`s`, size_t` size`, const wchar_t *`template`, va_list` ap`)`
  `wchar.h` (GNU): Variable Arguments Output.
`int vswscanf (const wchar_t *`s`, const wchar_t *`template`, va_list` ap`)`
  `wchar.h` (ISO): Variable Arguments Input.
`void vsyslog (int` facility_priority`, const char *`format`, va_list` arglist`)`
  `syslog.h` (BSD): syslog; vsyslog.
`int VTIME`
  `termios.h` (POSIX.1): Noncanonical Input.
`int vtimes (struct vtimes *`current`, struct vtimes *`child`)`
  `sys/vtimes.h` (sys/vtimes.h): Resource Usage.
`void vwarn (const char *`format`, va_list` ap`)`
  `err.h` (BSD): Error Messages.
`void vwarnx (const char *`format`, va_list` ap`)`
  `err.h` (BSD): Error Messages.
`int VWERASE`
  `termios.h` (BSD): Editing Characters.
`int vwprintf (const wchar_t *`template`, va_list` ap`)`
  `wchar.h` (ISO): Variable Arguments Output.
`int vwscanf (const wchar_t *`template`, va_list` ap`)`
  `wchar.h` (ISO): Variable Arguments Input.
`pid_t wait (int *`status-ptr`)`
  `sys/wait.h` (POSIX.1): Process Completion.
`pid_t wait3 (union wait *`status-ptr`, int` options`, struct rusage *`usage`)`
  `sys/wait.h` (BSD): BSD Wait Functions.
`pid_t wait4 (pid_t` pid`, int *`status-ptr`, int` options`, struct rusage *`usage`)`
  `sys/wait.h` (BSD): Process Completion.
`pid_t waitpid (pid_t` pid`, int *`status-ptr`, int` options`)`
  `sys/wait.h` (POSIX.1): Process Completion.
`void warn (const char *`format`, ...)`
  `err.h` (BSD): Error Messages.
`void warnx (const char *`format`, ...)`
  `err.h` (BSD): Error Messages.
`WCHAR_MAX`
  `limits.h` (GNU): Range of Type.
`wint_t WCHAR_MAX`
  `wchar.h` (ISO): Extended Char Intro.
`wint_t WCHAR_MIN`
  `wchar.h` (ISO): Extended Char Intro.
`wchar_t`
  `stddef.h` (ISO): Extended Char Intro.
`int WCOREDUMP (int` status`)`
  `sys/wait.h` (BSD): Process Completion Status.
`wchar_t * wcpcpy (wchar_t *restrict` wto`, const wchar_t *restrict` wfrom`)`
  `wchar.h` (GNU): Copying and Concatenation.
`wchar_t * wcpncpy (wchar_t *restrict` wto`, const wchar_t *restrict` wfrom`, size_t` size`)`
  `wchar.h` (GNU): Copying and Concatenation.
`size_t wcrtomb (char *restrict` s`, wchar_t` wc`, mbstate_t *restrict` ps`)`
  `wchar.h` (ISO): Converting a Character.
`int wcscasecmp (const wchar_t *`ws1`, const wchar_t *`ws2`)`
  `wchar.h` (GNU): String/Array Comparison.
`wchar_t * wcscat (wchar_t *restrict` wto`, const wchar_t *restrict` wfrom`)`
  `wchar.h` (ISO): Copying and Concatenation.
`wchar_t * wcschr (const wchar_t *`wstring`, int` wc`)`
  `wchar.h` (ISO): Search Functions.
`wchar_t * wcschrnul (const wchar_t *`wstring`, wchar_t` wc`)`
  `wchar.h` (GNU): Search Functions.
`int wcscmp (const wchar_t *`ws1`, const wchar_t *`ws2`)`
  `wchar.h` (ISO): String/Array Comparison.
`int wcscoll (const wchar_t *`ws1`, const wchar_t *`ws2`)`
  `wchar.h` (ISO): Collation Functions.
`wchar_t * wcscpy (wchar_t *restrict` wto`, const wchar_t *restrict` wfrom`)`
  `wchar.h` (ISO): Copying and Concatenation.
`size_t wcscspn (const wchar_t *`wstring`, const wchar_t *`stopset`)`
  `wchar.h` (ISO): Search Functions.
`wchar_t * wcsdup (const wchar_t *`ws`)`
  `wchar.h` (GNU): Copying and Concatenation.
`size_t wcsftime (wchar_t *`s`, size_t` size`, const wchar_t *`template`, const struct tm *`brokentime`)`
  `time.h` (ISO/Amend1): Formatting Calendar Time.
`size_t wcslen (const wchar_t *`ws`)`
  `wchar.h` (ISO): String Length.
`int wcsncasecmp (const wchar_t *`ws1`, const wchar_t *`s2`, size_t` n`)`
  `wchar.h` (GNU): String/Array Comparison.
`wchar_t * wcsncat (wchar_t *restrict` wto`, const wchar_t *restrict` wfrom`, size_t` size`)`
  `wchar.h` (ISO): Copying and Concatenation.
`int wcsncmp (const wchar_t *`ws1`, const wchar_t *`ws2`, size_t` size`)`
  `wchar.h` (ISO): String/Array Comparison.
`wchar_t * wcsncpy (wchar_t *restrict` wto`, const wchar_t *restrict` wfrom`, size_t` size`)`
  `wchar.h` (ISO): Copying and Concatenation.
`size_t wcsnlen (const wchar_t *`ws`, size_t` maxlen`)`
  `wchar.h` (GNU): String Length.
`size_t wcsnrtombs (char *restrict` dst`, const wchar_t **restrict` src`, size_t` nwc`, size_t` len`, mbstate_t *restrict` ps`)`
  `wchar.h` (GNU): Converting Strings.
`wchar_t * wcspbrk (const wchar_t *`wstring`, const wchar_t *`stopset`)`
  `wchar.h` (ISO): Search Functions.
`wchar_t * wcsrchr (const wchar_t *`wstring`, wchar_t` c`)`
  `wchar.h` (ISO): Search Functions.
`size_t wcsrtombs (char *restrict` dst`, const wchar_t **restrict` src`, size_t` len`, mbstate_t *restrict` ps`)`
  `wchar.h` (ISO): Converting Strings.
`size_t wcsspn (const wchar_t *`wstring`, const wchar_t *`skipset`)`
  `wchar.h` (ISO): Search Functions.
`wchar_t * wcsstr (const wchar_t *`haystack`, const wchar_t *`needle`)`
  `wchar.h` (ISO): Search Functions.
`double wcstod (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`)`
  `wchar.h` (ISO): Parsing of Floats.
`float wcstof (const wchar_t *`string`, wchar_t **`tailptr`)`
  `stdlib.h` (ISO): Parsing of Floats.
`intmax_t wcstoimax (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`, int` base`)`
  `wchar.h` (ISO): Parsing of Integers.
`wchar_t * wcstok (wchar_t *`newstring`, const wchar_t *`delimiters`)`
  `wchar.h` (ISO): Finding Tokens in a String.
`long int wcstol (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`, int` base`)`
  `wchar.h` (ISO): Parsing of Integers.
`long double wcstold (const wchar_t *`string`, wchar_t **`tailptr`)`
  `stdlib.h` (ISO): Parsing of Floats.
`long long int wcstoll (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`, int` base`)`
  `wchar.h` (ISO): Parsing of Integers.
`size_t wcstombs (char *`string`, const wchar_t *`wstring`, size_t` size`)`
  `stdlib.h` (ISO): Non-reentrant String Conversion.
`long long int wcstoq (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`, int` base`)`
  `wchar.h` (GNU): Parsing of Integers.
`unsigned long int wcstoul (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`, int` base`)`
  `wchar.h` (ISO): Parsing of Integers.
`unsigned long long int wcstoull (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`, int` base`)`
  `wchar.h` (ISO): Parsing of Integers.
`uintmax_t wcstoumax (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`, int` base`)`
  `wchar.h` (ISO): Parsing of Integers.
`unsigned long long int wcstouq (const wchar_t *restrict` string`, wchar_t **restrict` tailptr`, int` base`)`
  `wchar.h` (GNU): Parsing of Integers.
`wchar_t * wcswcs (const wchar_t *`haystack`, const wchar_t *`needle`)`
  `wchar.h` (XPG): Search Functions.
`size_t wcsxfrm (wchar_t *restrict` wto`, const wchar_t *`wfrom`, size_t` size`)`
  `wchar.h` (ISO): Collation Functions.
`int wctob (wint_t` c`)`
  `wchar.h` (ISO): Converting a Character.
`int wctomb (char *`string`, wchar_t` wchar`)`
  `stdlib.h` (ISO): Non-reentrant Character Conversion.
`wctrans_t wctrans (const char *`property`)`
  `wctype.h` (ISO): Wide Character Case Conversion.
`wctrans_t`
  `wctype.h` (ISO): Wide Character Case Conversion.
`wctype_t wctype (const char *`property`)`
  `wctype.h` (ISO): Classification of Wide Characters.
`wctype_t`
  `wctype.h` (ISO): Classification of Wide Characters.
`int WEOF`
  `wchar.h` (ISO): EOF and Errors.
`wint_t WEOF`
  `wchar.h` (ISO): Extended Char Intro.
`int WEXITSTATUS (int` status`)`
  `sys/wait.h` (POSIX.1): Process Completion Status.
`int WIFEXITED (int` status`)`
  `sys/wait.h` (POSIX.1): Process Completion Status.
`int WIFSIGNALED (int` status`)`
  `sys/wait.h` (POSIX.1): Process Completion Status.
`int WIFSTOPPED (int` status`)`
  `sys/wait.h` (POSIX.1): Process Completion Status.
`wint_t`
  `wchar.h` (ISO): Extended Char Intro.
`wchar_t * wmemchr (const wchar_t *`block`, wchar_t` wc`, size_t` size`)`
  `wchar.h` (ISO): Search Functions.
`int wmemcmp (const wchar_t *`a1`, const wchar_t *`a2`, size_t` size`)`
  `wchar.h` (ISO): String/Array Comparison.
`wchar_t * wmemcpy (wchar_t *restrict` wto`, const wchar_t *restrict` wfrom`, size_t` size`)`
  `wchar.h` (ISO): Copying and Concatenation.
`wchar_t * wmemmove (wchar_t *`wto`, const wchar_t *`wfrom`, size_t` size`)`
  `wchar.h` (ISO): Copying and Concatenation.
`wchar_t * wmempcpy (wchar_t *restrict` wto`, const wchar_t *restrict` wfrom`, size_t` size`)`
  `wchar.h` (GNU): Copying and Concatenation.
`wchar_t * wmemset (wchar_t *`block`, wchar_t` wc`, size_t` size`)`
  `wchar.h` (ISO): Copying and Concatenation.
`int W_OK`
  `unistd.h` (POSIX.1): Testing File Access.
`int wordexp (const char *`words`, wordexp_t *`word-vector-ptr`, int` flags`)`
  `wordexp.h` (POSIX.2): Calling Wordexp.
`wordexp_t`
  `wordexp.h` (POSIX.2): Calling Wordexp.
`void wordfree (wordexp_t *`word-vector-ptr`)`
  `wordexp.h` (POSIX.2): Calling Wordexp.
`int wprintf (const wchar_t *`template`, ...)`
  `wchar.h` (ISO): Formatted Output Functions.
`WRDE_APPEND`
  `wordexp.h` (POSIX.2): Flags for Wordexp.
`WRDE_BADCHAR`
  `wordexp.h` (POSIX.2): Calling Wordexp.
`WRDE_BADVAL`
  `wordexp.h` (POSIX.2): Calling Wordexp.
`WRDE_CMDSUB`
  `wordexp.h` (POSIX.2): Calling Wordexp.
`WRDE_DOOFFS`
  `wordexp.h` (POSIX.2): Flags for Wordexp.
`WRDE_NOCMD`
  `wordexp.h` (POSIX.2): Flags for Wordexp.
`WRDE_NOSPACE`
  `wordexp.h` (POSIX.2): Calling Wordexp.
`WRDE_REUSE`
  `wordexp.h` (POSIX.2): Flags for Wordexp.
`WRDE_SHOWERR`
  `wordexp.h` (POSIX.2): Flags for Wordexp.
`WRDE_SYNTAX`
  `wordexp.h` (POSIX.2): Calling Wordexp.
`WRDE_UNDEF`
  `wordexp.h` (POSIX.2): Flags for Wordexp.
`ssize_t write (int` filedes`, const void *`buffer`, size_t` size`)`
  `unistd.h` (POSIX.1): I/O Primitives.
`ssize_t writev (int` filedes`, const struct iovec *`vector`, int` count`)`
  `sys/uio.h` (BSD): Scatter-Gather.
`int wscanf (const wchar_t *`template`, ...)`
  `wchar.h` (ISO): Formatted Input Functions.
`int WSTOPSIG (int` status`)`
  `sys/wait.h` (POSIX.1): Process Completion Status.
`int WTERMSIG (int` status`)`
  `sys/wait.h` (POSIX.1): Process Completion Status.
`int X_OK`
  `unistd.h` (POSIX.1): Testing File Access.
`_XOPEN_SOURCE`
  (X/Open): Feature Test Macros.
`_XOPEN_SOURCE_EXTENDED`
  (X/Open): Feature Test Macros.
`double y0 (double` x`)`
  `math.h` (SVID): Special Functions.
`float y0f (float` x`)`
  `math.h` (SVID): Special Functions.
`long double y0l (long double` x`)`
  `math.h` (SVID): Special Functions.
`double y1 (double` x`)`
  `math.h` (SVID): Special Functions.
`float y1f (float` x`)`
  `math.h` (SVID): Special Functions.
`long double y1l (long double` x`)`
  `math.h` (SVID): Special Functions.
`double yn (int` n`, double` x`)`
  `math.h` (SVID): Special Functions.
`float ynf (int` n`, float` x`)`
  `math.h` (SVID): Special Functions.
`long double ynl (int` n`, long double` x`)`
  `math.h` (SVID): Special Functions.