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GETGROUPS(2) |
System Calls Manual |
GETGROUPS(2) |
NAME
getgroups — get group access list
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
int
getgroups(int gidsetlen, gid_t *gidset);
DESCRIPTION
getgroups() gets the current group access list of the current user process and stores it in the array
gidset. The parameter
gidsetlen indicates the number of entries that may be placed in
gidset.
getgroups() returns the actual number of groups returned in
gidset. No more than {
NGROUPS_MAX} will ever be returned. If
gidsetlen is 0,
getgroups() returns the number of groups without modifying the
gidset array.
This system call only returns the secondary groups.
RETURN VALUES
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.
ERRORS
The possible errors for
getgroups() are:
-
[EINVAL]
-
The argument gidsetlen is non-zero and is smaller than the number of groups in the group set.
-
[EFAULT]
-
The argument gidset specifies an invalid address.
STANDARDS
The getgroups() function conforms to IEEE Std 1003.1-1990 (“POSIX.1”).
HISTORY
The getgroups() function call appeared in 4.2BSD.
