Manual Pages  — GETGROUPS

getgroups – get group access list

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES ERRORS SEE ALSO STANDARDS HISTORY

Standard C Library (libc, -lc)

#include <unistd.h>

int
getgroups(int gidsetlen, gid_t *gidset);

A successful call returns the number of groups in the group set. A value of -1 indicates that an error occurred, and the error code is stored in the global variable errno.

The possible errors for getgroups() are:

[EINVAL]
	The argument gidsetlen is smaller than the number of groups in the group set.
[EFAULT]
	The argument gidset specifies an invalid address.

The getgroups() system call conforms to IEEE Std 1003.1-2008 ("POSIX.1").

The getgroups() system call appeared in BSD 4.2 .