initgroups

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

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 re-
       turned, and errno is set appropriately.

ERRORS
       ENOMEM Insufficient memory to allocate group information structure.

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

FILES
       /etc/group
              group database file

ATTRIBUTES
       For  an  explanation  of  the  terms  used  in  this  section,  see at-
       tributes(7).

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

CONFORMING TO
       SVr4, 4.3BSD.

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

COLOPHON
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       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.

GNU                               2017-09-15                     INITGROUPS(3)