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

NAME
     getpgrp, getpgid -- get process group

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <unistd.h>

     pid_t
     getpgrp(void);

     pid_t
     getpgid(pid_t pid);

DESCRIPTION
     The process group of the current process is returned by getpgrp().	 The
     process group of the pid process is returned by getpgid().

     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 tcgetpgrp() and tcsetpgrp()
     calls are used to get/set the process group of the	control	terminal.

ERRORS
     getpgrp() always succeeds,	however	getpgid() will succeed unless:

     [ESRCH]		if there is no process with a process ID equal to pid.

SEE ALSO
     setpgid(2), termios(4)

STANDARDS
     The getpgrp() function conforms to	IEEE Std 1003.1-1988 ("POSIX.1").

HISTORY
     The getpgrp() function call appeared in 4.0BSD.  The getpgid() function
     call is derived from its usage in AT&T System V Release 4 UNIX, and first
     appeared in NetBSD	1.3.

COMPATIBILITY
     This version of getpgrp() differs from past Berkeley versions by not tak-
     ing a pid_t 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 getpgrp() 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 System V getpgrp() suffices, and
     the added complexity of the 4.3BSD	getpgrp() has been omitted from
     POSIX.1.  The old functionality is	available from the getpgid() function.

BSD				August 11, 2002				   BSD

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ERRORS | SEE ALSO | STANDARDS | HISTORY | COMPATIBILITY

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