getpgrp(2) System Calls Manual getpgrp(2)Name
getpgrp - get process group
Syntax
#include <sys/types.h>
#include <unistd.h>
pgrp = getpgrp(pid)
pid_t pgrp;
pid_t pid;
Description
The system call returns the process group of the specified process. If pid is zero, the call applies to 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 the foreground and may read, while others block with a signal if they attempt to read.
This call is used by programs such as to create process groups in implementing job control. The TIOCGPGRP and TIOCSPGRP calls described in
are used to get and set the process group of the control terminal.
Environment
When your program is compiled in the System V or POSIX environment, is called without arguments and the process group of the current
process is returned.
Additionally, in POSIX mode, returns a value type of pid_t.
Diagnostics
The call fails under the following condition:
[ESRCH] No such process, PID.
See Alsogetuid(2), setpgrp(2), tty(4)getpgrp(2)
Check Out this Related Man Page
GETPGRP(2) BSD System Calls Manual GETPGRP(2)NAME
getpgid, getpgrp -- get process group
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
pid_t
getpgid(pid_t pid);
pid_t
getpgrp(void);
DESCRIPTION
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 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.
RETURN VALUES
The getpgrp() call always succeeds. Upon successful completion, the getpgid() call returns the process group of the specified process; oth-
erwise, it returns a value of -1 and sets errno to indicate the error.
ERRORS
getpgid() will succeed unless:
[ESRCH] There is no process whose process ID equals pid.
SEE ALSO getsid(2), setpgid(2), termios(4)HISTORY
The getpgrp() function call appeared in 4.0BSD. The getpgid() function call is derived from its usage in System V Release 4.
STANDARDS
The getpgrp() function call is expected to conform to ISO/IEC 9945-1:1990 (``POSIX.1'').
COMPATIBILITY
This version of getpgrp() differs from past Berkeley versions by not taking 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 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() function.
BSD June 4, 1993 BSD
1 . Thanks you for reading the letter
2 . I have programe a X-application .Sometimes, I run it from terminal of CDE ,it "kill" the CDE and I meet the login dialog . I debug it . I find that the SIGHUP caused the X-app died .I do not run it from terminal of CDE ,I run it "click button" from panel ,... (3 Replies)
Hi,
I want to fork a new process from a daemon that needs terminal attachment to some ttyN or pts/N device. Here is the code
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <string.h>
int main(int... (5 Replies)
Hello,
How many child processes are actually created when running this code ?
#include <signal.h>
#include <stdio.h>
int main () {
int i ;
setpgrp () ;
for (i = 0; i < 10; i++) {
if (fork () == 0) {
if ( i & 1 ) setpgrp () ;
printf ("Child id: %2d, group: %2d\n", getpid(),... (0 Replies)
Hello,
How many child processes are actually created when running this code ?
#include <signal.h>
#include <stdio.h>
int main () {
int i ;
setpgrp () ;
for (i = 0; i < 10; i++) {
if (fork () == 0) {
if ( i & 1 ) setpgrp () ;
printf ("Child id: %2d, group: %2d\n",... (1 Reply)
Hey,
I have a Red Hat 5.2 machine with :
2.6.18-92.el5 kernel
PRM's:
openssh-4.3p2-29.el5
openssh-clients-4.3p2-29.el5
openssl-0.9.8e-7.el5
openssh-server-4.3p2-29.el5
openssl-0.9.8b-10.el5
openssl-devel-0.9.8e-7.el5
openssh-askpass-4.3p2-29.el5
I'm trying to transfer files to a... (2 Replies)
Hi, guys:
I am working on my own shell using c. When I put a process into the background, how can I put it back to the foreground using tcsetpgrp?
Thanks (3 Replies)
Hi again ;) Now I want to make a program that will execute the programs with exec, asking the user if he wants the program to run in background or foreground.
scanf("%c",&caracter);
if (caracter=='y'){
printf("Has decidido ejecutarlo en background\n");
if((pid=fork())==0) {// fork para... (3 Replies)
Hello All,
Sendmail takes too long to start and the host is unable to send emails, below are the steps followed, Please let me know if I'm missing anything, is there a debug mode for mailx?
# time service sendmail restart
Shutting down sm-client:
Shutting... (6 Replies)
Hi Forum.
I have an XML file with the following requirement to move the <AdditionalAccountHolders> tag and its content right after the <accountHolderName> tag within the same file but I'm not sure how to accomplish this through a Unix script.
Any feedback will be greatly appreciated.
... (19 Replies)