If the current process is not already a session leader, the setpgrp utility sets the process group ID and session ID to the current process ID and does an exec() of command and its argument(s), if any.
The following operands are supported:
The following exit values are returned:
Otherwise, the exit status will be that of command.
See attributes(5) for descriptions of the following attributes:
exec(2), setpgrp(2), attributes(5)