GETPGRP(2) BSD System Calls Manual GETPGRP(2)

NAME
     ggeettppggiidd, ggeettppggrrpp - get process group

LLIIBBRRAARRYY
     Standard C Library (libc, -lc)

SYNOPSIS
     ##iinncclluuddee <>

     pidt
     ggeettppggiidd(pidt pid);

     pidt
     ggeettppggrrpp(void);

DESCRIPTION
     The process group of the current process is returned by ggeettppggrrpp().  The
     process group of the process identified by pid is returned by ggeettppggiidd().
     If pid is zero, ggeettppggiidd() returns the process group of the current
     process.

     Process groups are used for distribution of signals, and by terminals to
     arbitrate requests for their input: processes that have the same process
     group as the terminal are foreground and may read, while others will
     block with a signal if they attempt to read.

     This call is thus used by programs such as csh(1) to create process
     groups in implementing job control.  The ttccggeettppggrrpp() and ttccsseettppggrrpp()
     calls are used to get/set the process group of the control terminal.

RETURN VALUES
     The ggeettppggrrpp() call always succeeds.  Upon successful completion, the
     ggeettppggiidd() call returns the process group of the specified process; other-
     wise, it returns a value of -1 and sets errno to indicate the error.

EERRRROORRSS
     ggeettppggiidd() will succeed unless:

     [ESRCH]            There is no process whose process ID equals pid.

SEE ALSO
     getsid(2), setpgid(2), termios(4)

HISTORY     The ggeettppggrrpp() function call appeared in 4.0BSD.  The ggeettppggiidd() function
     call is derived from its usage in System V Release 4.

STANDARDS
     The ggeettppggrrpp() function call is expected to conform to ISO/IEC 9945-1:1990
     (``POSIX.1'').

CCOOMMPPAATTIIBBIILLIITTYY
     This version of ggeettppggrrpp() differs from past Berkeley versions by not tak-
     ing a pidt pid argument.  This incompatibility is required by ISO/IEC
     9945-1:1990 (``POSIX.1'').

     From the ISO/IEC 9945-1:1990 (``POSIX.1'') Rationale:

     4.3BSD provides a ggeettppggrrpp() function that returns the process group ID
     for a specified process.  Although this function is used to support job
     control, all known job-control shells always specify the calling process
     with this function.  Thus, the simpler AT&T System V UNIX ggeettppggrrpp() suf-
     fices, and the added complexity of the 4.3BSD ggeettppggrrpp() has been omitted
     from POSIX.1.  The old functionality is available from the ggeettppggiidd()
     function.

BSD                              June 4, 1993                              BSD