bsd man page for setpgrp

SETPGRP(2)							System Calls Manual							SETPGRP(2)

NAME
       setpgrp - set process group

SYNOPSIS
       setpgrp(pid, pgrp)
       int pid, pgrp;

DESCRIPTION
       Setpgrp	sets  the  process group of the specified process pid to the specified pgrp.  If pid is zero, then the call applies to the current
       process.

       If the invoker is not the super-user, then the affected process must have the same effective user-id as the invoker or be a  descendant	of
       the invoking process.

RETURN VALUE
       Setpgrp	returns when the operation was successful.  If the request failed, -1 is returned and the global variable errno indicates the rea-
       son.

ERRORS
       Setpgrp will fail and the process group will not be altered if one of the following occur:

       [ESRCH]	      The requested process does not exist.

       [EPERM]	      The effective user ID of the requested process is different from that of the caller and the process is not a  descendent	of
		      the calling process.

SEE ALSO
       getpgrp(2)

4th Berkeley Distribution					    May 9, 1985 							SETPGRP(2)