tcgetpgrp, tcsetpgrp - get and set terminal foreground process group
The function tcgetpgrp() returns the process group
ID of the foreground process group on the terminal associated to
fd, which must be the controlling terminal of the calling
The function tcsetpgrp() makes the process group
with process group ID
pgrp the foreground process group on the
terminal associated to
fd, which must be the controlling
terminal of the calling process, and still be associated with its
pgrp must be a (nonempty) process group
belonging to the same session as the calling process.
If tcsetpgrp() is called by a member of a background process group in its session, and the calling process is not blocking or ignoring SIGTTOU, a SIGTTOU signal is sent to all members of this background process group.
fd refers to the controlling terminal of the calling
process, the function tcgetpgrp() 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.
fd does not refer to the controlling terminal of the
calling process, -1 is returned, and
errno is set
When successful, tcsetpgrp() returns 0. Otherwise,
it returns -1, and
errno is set appropriately.
fd is not a valid file descriptor.
pgrp has an unsupported value.
The calling process does not have a controlling terminal, or it has
one but it is not described by
fd, or, for
tcsetpgrp(), this controlling terminal is no longer
associated with the session of the calling process.
pgrp has a supported value, but is not the process group ID
of a process in the same session as the calling process.
These functions are implemented via the TIOCGPGRP and TIOCSPGRP ioctls.
The ioctls appeared in 4.2BSD. The functions are POSIX inventions.
This page is part of release 5.10 of the Linux
project. A description of the project, information about reporting bugs,
and the latest version of this page, can be found at