2.9BSD/usr/man/cat2/setpgrp.2j

SETPGRP(2J)         UNIX Programmer's Manual          SETPGRP(2J)

NAME
     setpgrp, getpgrp - set/get process group

SYNOPSIS
     int getpgrp(pid)

     setpgrp(pid, pgrp)

     cc ... -ljobs

DESCRIPTION
     The process group of the specified process is returned by
     _g_e_t_p_g_r_p. _S_e_t_p_g_r_p sets the process group of the specified
     process _p_i_d to the specified _p_g_r_p. If _p_i_d is zero, then the
     call applies to the current process.

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

     This call is used by _c_s_h(1) to create process groups in
     implementing job control.  The TIOCGPGRP and TIOCSPGRP calls
     described in _t_t_y(4) are used to get/set the process group of
     the control terminal.

     See _i_n_t_r_o(3J) for a general discussion of job control.

ERRORS
     _S_e_t_p_g_r_p will fail and the process group will not be altered
     if one of the following is true:

     [ESRCH]             The reqoested process does not exist.

     [EPERM]             The effective user ID of the request
                         process is diferent from that of the
                         caller and the process is not a descen-
                         dent of the calling process.

SEE ALSO
     csh(1), getuid(2), intro(3J), tty(4)

ASSEMBLER (PDP-11)
     (setpgrp = 39.)
     (process id in r0)
     sys setpgrp; newgrp

     (getpgrp is implemented as setpgrp(pid,-1))
     sys setgrp; -1
     (process group in r0)

BUGS
     The job control facilities are not available in standard

Printed 5/27/83                                                 1

SETPGRP(2J)         UNIX Programmer's Manual          SETPGRP(2J)

     version 7 UNIX.  These facilities are still under develop-
     ment and may change in future releases of the system as
     better inter-process communication facilities and support
     for virtual terminals become available.  The options and
     specifications of these system calls and even the calls
     themselves are thus subject to change.

     A system call _s_e_t_p_g_r_p has been implemented in other versions
     of UNIX which are not widely used outside of Bell Labora-
     tories; these implementations have, in general, slightly
     different semantics.

Printed 5/27/83                                                 2