initgroups(3) - BetterMan

initgroups(3)

initialize the supplementary group access list

distropkg manpages-dev@6.9.1-1dataset 2026-04-01T06:19:02Z+debian+ec4110e+mandoc:1.14.6-4

Synopsis

#include <sys/types.h>
#include <grp.h>
int initgroups(const char *
user
, gid_t 
group
);
initgroups
():
Since glibc 2.19:
        _DEFAULT_SOURCE
    glibc 2.19 and earlier:
        _BSD_SOURCE

—

Options · 3

ENOMEM	Insufficient memory to allocate group information structure.
EPERM	The calling process has insufficient privilege. See the underlying system call setgroups(2).
/etc/group	group database file

NAME

initgroups - initialize the supplementary group access list

SYNOPSIS

bash

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

bash

int initgroups(const char *\nuser\n, gid_t \ngroup\n);

initgroups():

bash


\n
    Since glibc 2.19:
\n
        _DEFAULT_SOURCE
\n
    glibc 2.19 and earlier:
\n
        _BSD_SOURCE

The initgroups() function initializes the group access list by reading the group database /etc/group and using all groups of which user is a member. The additional group group is also added to the list.

The user argument must be non-NULL.

RETURN VALUE

The initgroups() function returns 0 on success. On error, -1 is returned, and errno is set to indicate the error.

ERRORS

ENOMEM: Insufficient memory to allocate group information structure.
EPERM: The calling process has insufficient privilege. See the underlying system call setgroups(2).