setgid

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 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 program that is not
       suid root to drop all of its group privileges,  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 (does not have the CAP_SETGID
              capability), 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(2), setregid(2), setegid(2)



Linux 2.5                         2002-03-09                         SETGID(2)