#### 29.14.1 The Data Structure for a Group

The functions and data structures for accessing the system group database are declared in the header file `grp.h`.

— Data Type: struct group

> The `group` structure is used to hold information about an entry in the system group database. It has at least the following members:

> `char *gr_name`
>   The name of the group.
> `gid_t gr_gid`
>   The group ID of the group.
> `char **gr_mem`
>   A vector of pointers to the names of users in the group. Each user name is a null-terminated string, and the vector itself is terminated by a null pointer.