SYNOPSIS
       #include <unistd.h>

       int setegid(gid_t gid);


DESCRIPTION
       If  gid  is equal to the real group ID or the saved set-group-ID, or if
       the process has appropriate privileges, setegid() shall set the  effec-
       tive  group  ID of the calling process to gid; the real group ID, saved
       set-group-ID, and any supplementary group IDs shall remain unchanged.

       The setegid() function shall not affect the supplementary group list in
       any way.

RETURN VALUE
       Upon successful completion, 0 shall be returned; otherwise, -1 shall be
       returned and errno set to indicate the error.

ERRORS
       The setegid() function shall fail if:

       EINVAL The value of the gid argument is invalid and is not supported by
              the implementation.

       EPERM  The  process  does  not have appropriate privileges and gid does
              not match the real group ID or the saved set-group-ID.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       Refer to the RATIONALE section in setuid() .

FUTURE DIRECTIONS
       None.

SEE ALSO
       exec() , getegid() , geteuid() , getgid() , getuid() , seteuid() , set-
       gid()  , setregid() , setreuid() , setuid() , the Base Definitions vol-
       ume of IEEE Std 1003.1-2001, <sys/types.h>, <unistd.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base