SETGID(2)                                           Linux Programmer's Manual                                          SETGID(2)



NAME
       setgid - set group identity

SYNOPSIS
       #include <sys/types.h>
       #include <unistd.h>

       int setgid(gid_t gid);

DESCRIPTION
       setgid() sets the effective group ID of the calling process.  If the caller is the superuser, the real GID and saved set-
       group-ID are also set.

       Under Linux, setgid() is implemented like the POSIX version with the _POSIX_SAVED_IDS feature.  This allows a  set-group-
       ID  program  that is not set-user-ID-root to drop all of its group privileges, do some un-privileged work, and then reen-
       gage the original effective group ID in a secure manner.

RETURN VALUE
       On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.

ERRORS
       EPERM  The calling process is not privileged (does not have the CAP_SETGID capability), and gid does not match  the  real
              group ID or saved set-group-ID of the calling process.

CONFORMING TO
       SVr4, POSIX.1-2001.

SEE ALSO
       getgid(2), setegid(2), setregid(2), capabilities(7), credentials(7)

COLOPHON
       This  page  is  part of release 3.25 of the Linux man-pages project.  A description of the project, and information about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



Linux                                                      2009-10-17                                                  SETGID(2)