www.LinuxHowtos.org

INITGROUPS

Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
Index Return to Main Contents

NAME

initgroups - initialize the supplementary group access list

SYNOPSIS

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

int initgroups(const char *user, gid_t group);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

initgroups():
    Since glibc 2.19:
        _DEFAULT_SOURCE
    Glibc 2.19 and earlier:
        _BSD_SOURCE

DESCRIPTION

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 appropriately.

ERRORS

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

FILES

/etc/group              group database file

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
initgroups()	Thread safety	MT-Safe locale

CONFORMING TO

SVr4, 4.3BSD.

COLOPHON

This page is part of release 4.13 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.