HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. |  |
NAME |LIBRARY |SYNOPSIS |DESCRIPTION |RETURN VALUE |ERRORS |ATTRIBUTES |VERSIONS |STANDARDS |HISTORY |SEE ALSO |COLOPHON | |
tcgetpgrp(3) Library Functions Manualtcgetpgrp(3)tcgetpgrp, tcsetpgrp - get and set terminal foreground process group
Standard C library (libc,-lc)
#include <unistd.h>pid_t tcgetpgrp(intfd);int tcsetpgrp(intfd, pid_tpgrp);
The functiontcgetpgrp() returns the process group ID of the foreground process group on the terminal associated tofd, which must be the controlling terminal of the calling process. The functiontcsetpgrp() makes the process group with process group IDpgrp the foreground process group on the terminal associated tofd, which must be the controlling terminal of the calling process, and still be associated with its session. Moreover,pgrp must be a (nonempty) process group belonging to the same session as the calling process. Iftcsetpgrp() is called by a member of a background process group in its session, and the calling process is not blocking or ignoringSIGTTOU, aSIGTTOUsignal is sent to all members of this background process group.
Whenfd refers to the controlling terminal of the calling process, the functiontcgetpgrp() will return the foreground process group ID of that terminal if there is one, and some value larger than 1 that is not presently a process group ID otherwise. Whenfd does not refer to the controlling terminal of the calling process, -1 is returned, anderrno is set to indicate the error. When successful,tcsetpgrp() returns 0. Otherwise, it returns -1, anderrno is set to indicate the error.
EBADFfd is not a valid file descriptor.EINVALpgrp has an unsupported value.ENOTTYThe calling process does not have a controlling terminal, or it has one but it is not described byfd, or, fortcsetpgrp(), this controlling terminal is no longer associated with the session of the calling process.EPERMpgrp has a supported value, but is not the process group ID of a process in the same session as the calling process.
For an explanation of the terms used in this section, seeattributes(7). ┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface│Attribute│Value│ ├──────────────────────────────────────┼───────────────┼─────────┤ │tcgetpgrp(),tcsetpgrp() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘
These functions are implemented via theTIOCGPGRPandTIOCSPGRP ioctls.
POSIX.1-2008.
POSIX.1-2001. The ioctls appeared in 4.2BSD. The functions are POSIX inventions.
setpgid(2),setsid(2),credentials(7)
This page is part of theman-pages (Linux kernel and C library user-space interface documentation) project. Information about the project can be found at ⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report for this manual page, see ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩. This page was obtained from the tarball man-pages-6.15.tar.gz fetched from ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on 2025-08-11. If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up- to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which isnot part of the original manual page), send a mail to man-pages@man7.orgLinux man-pages 6.15 2025-05-17tcgetpgrp(3)Pages that refer to this page:setpgid(2), TIOCSPGRP(2const), credentials(7), signal-safety(7)
HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. | |