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



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 current process.
       If the caller is the superuser, the real and  saved  group
       ID's are also set.

       Under  Linux, setgid is implemented like the POSIX version
       with the _POSIX_SAVED_IDS feature.  This allows  a  setgid
       (other  than root) program to drop all of its group privi-
       leges, do some un-privileged work, and then re-engage  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 user is not the super-user, and  gid  does  not
              match  the effective group ID or saved set-group-ID
              of the calling process.

CONFORMING TO
       SVr4, SVID.

SEE ALSO
       getgid(d), setregid(d), setegid(d)



Linux 1.1.36                1994-07-29                  SETGID(D)