initgroups(3) Linux Man Page

Name

initgroups - initialize the supplementary group access list

Library

Standard C library ( libc ", " -lc )

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 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).

Files

/etc/group group database file

Attributes

For an explanation of the terms used in this section, see attributes(7). allbox; lbx lb lb T{ initgroups()

Interface	Attribute	Value
T}	Thread safety	MT-Safe locale

Standards

None.

History

SVr4, 4.3BSD.

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