initgroups(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | FILES | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON

INITGROUPS(3)           Linux Programmer's Manual          INITGROUPS(3)

NAME         top

       initgroups - initialize the supplementary group access list

SYNOPSIS         top

       #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         top

       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         top

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

ERRORS         top

       ENOMEM Insufficient memory to allocate group information
              structure.

       EPERM  The calling process has insufficient privilege.  See the
              underlying system call setgroups(2).

FILES         top

       /etc/group
              group database file

ATTRIBUTES         top

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

       ┌─────────────┬───────────────┬────────────────┐
       │Interface    Attribute     Value          │
       ├─────────────┼───────────────┼────────────────┤
       │initgroups() │ Thread safety │ MT-Safe locale │
       └─────────────┴───────────────┴────────────────┘

CONFORMING TO         top

       SVr4, 4.3BSD.

SEE ALSO         top

       getgroups(2), setgroups(2), credentials(7)

COLOPHON         top

       This page is part of release 5.10 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/.

GNU                            2017-09-15                  INITGROUPS(3)

Pages that refer to this page: setpriv(1)getgroups(2)group(5)nss(5)credentials(7)