getgrgid - get group file entry for group ID

Syntax	#include <grp.h> Optional #include <sys/types.h> (End) struct group *getgrgid(gid_t gid);
Description	getgrgid() searches the group file for an entry containing a gr_gid component that matches gid (see grp.h and the manual "POSIX Basics" [1 (Related publications)]). getgrgid() is not thread-safe. Use the reentrant function getgrgid_r() when needed.
Return val.	Pointer to an object of the structure group
		if an entry with a gr_gid component matching gid is found.
	Null pointer	if an error occurs or no entry with a gr_gid component matching gid is found. errno is set to indicate the error.
Errors	getgrgid() fails if:
	EIO EINTR EMFILE ENFILE	An I/O error occurred. A signal was caught during the execution of getgrgid(). Too many file descriptors are currently open in the calling process. The file table of the system is currently full.
Notes	The return value may point to a static area which may be overwritten by a subsequent call to getgrgid() or getgrnam(). Since getgrgid() calls functions for file processing that may fail, errno should be set to o before the call to getgrgid(). If errno is set to some other value on return from the function, an error has occurred.
See also	getgrgid_r(), getgrnam(), grp.h, limits.h, sys/types.h, and the manual "POSIX Basics" [1 (Related publications)].