SETPGID Section: Linux Programmer's Manual (2) Updated: 15 April 2025 Index   NAME setpgid, getpgid, setpgrp, getpgrp - set/get process group   SYNOPSIS #include <unistd.h> int setpgid(pid_t pid, pid_t pgid); pid_t getpgid(pid_t pid); int setpgrp(void); pid_t getpgrp(void);   DESCRIPTION setpgid sets the process group ID of the process specified by pid to pgid. If pid is zero, the process ID of the current process is used. If pgid is zero, the process ID of the process specified by pid is used. getpgid returns the process group ID of the process specified by pid. If pid is zero, the process ID of the current process is used. In the Linux DLL 4.4.1 library, setpgrp simply calls setpgid(0,0). getpgrp is equivalent to getpgid(0). 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. These calls are thus used by programs such as to create process groups in implementing job control. The TIOCGPGRP and TIOCSPGRP calls described in are used to get/set the process group of the control terminal.   RETURN VALUE On success, setpgid and setpgrp return zero. On error, -1 is returned, and errno is set appropriately. getpgid returns a process group on success. On error, -1 is returned, and errno is set appropriately. getpgrp always returns the current process group.   ERRORS EINVAL pgid is less than 0. EPERM Various permission violations. ESRCH pid does not match any process.   CONFORMING TO SVr4, POSIX, 4.4BSD.   CONFORMING TO The functions setpgid and getpgrp conform to POSIX.1. The function setpgrp is from BSD 4.2. The function getpgid conforms to SVr4.   SEE ALSO   Index NAME SYNOPSIS DESCRIPTION RETURN VALUE ERRORS CONFORMING TO CONFORMING TO SEE ALSO This document was created by using the manual pages. Time: 11:56:07 GMT, March 24, 2025