getgrgid -- Access Group Database by ID

SYNOPSIS

 #include <sys/types.h>
 #include <grp.h>

 struct group *getgrgid(gid_t gid);

DESCRIPTION

getgrgid provides information about a group and its members. gid is the group ID. getgrgid returns a pointer to a group structure defined in <grp.h> that contains an entry from the group database. group contains the following members:

gr_name: name of the group
gr_gid: numerical group ID
gr_mem: null-terminated vector of pointers to the member names.

RETURN VALUE

getgrgid returns a pointer to a group structure if successful. getgrgid returns a NULL pointer if unsuccessful.

Note: The pointer returned by getgrgid may be a static data area that can be rewritten by the next call to getgrgid or getgrnam.

EXAMPLE

The following code fragment illustrates the use of getgrgid to obtain a group name:

 #include <sys/types.h>
 #include <stdio.h>
 #include <grp.h>
 #include <sys/stat.h>

 .
 .
 .

 struct stat info;
 struct group *grp;

 .
 .
 .
 
 if ((grp = getgrgid(info.st_gid)) == NULL)
    perror("getgrgid() error");
 else
    printf("The group name is %sn", grp->gr_name);

 .
 .
 .

RELATED FUNCTIONS

getgrnam, getgroups, getpwuid