GETGROUPS(2) BSD System Calls Manual GETGROUPS(2)NAMEgetgroups — get group access list
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
int
getgroups(int gidsetlen, gid_t *gidset);
DESCRIPTIONgetgroups() gets the current group access list of the current user
process and stores it in the array gidset. The parameter gidsetlen indi‐
cates 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.
SEE ALSOgetegid(2), getgid(2), setgroups(2), initgroups(3)STANDARDS
The getgroups() function conforms to ISO/IEC 9945-1:1990 (“POSIX.1”).
HISTORY
The getgroups() function call appeared in 4.2BSD.
BSD October 7, 2006 BSD