GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages
GETPGRP(2) FreeBSD System Calls Manual GETPGRP(2)

getpgrp
get process group

Standard C Library (libc, -lc)

#include <unistd.h>

pid_t
getpgrp(void);

pid_t
getpgid(pid_t pid);

The process group of the current process is returned by getpgrp(). The process group of the process identified by pid is returned by getpgid(). If pid is zero, getpgid() 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 system 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.

The getpgrp() system call always succeeds. Upon successful completion, the getpgid() system call returns the process group of the specified process; otherwise, it returns a value of -1 and sets errno to indicate the error.

This version of getpgrp() differs from past Berkeley versions by not taking a pid_t pid argument. This incompatibility is required by IEEE Std 1003.1-1990 (“POSIX.1”).

From the IEEE Std 1003.1-1990 (“POSIX.1”) Rationale:

4.3BSD provides a getpgrp() system call 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 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() system call.

The getpgid() system call will succeed unless:
[]
there is no process whose process ID equals pid

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

The getpgrp() system call is expected to conform to IEEE Std 1003.1-1990 (“POSIX.1”).

The getpgrp() system call appeared in 4.0BSD. The getpgid() system call is derived from its usage in AT&T System V Release 4 UNIX.
June 4, 1993 FreeBSD 13.1-RELEASE

Search for    or go to Top of page |  Section 2 |  Main Index

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with ManDoc.