| tcsetpgrp(3) - phpMan
TCGETPGRP(3) Linux Programmer's Manual TCGETPGRP(3)
NAME
tcgetpgrp, tcsetpgrp - get and set terminal foreground process group
SYNOPSIS
#include <unistd.h>
pid_t tcgetpgrp(int fd);
int tcsetpgrp(int fd, pid_t pgrp);
DESCRIPTION
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
process.
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 session. Moreover, 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 mem‐
bers of this background process group.
RETURN VALUE
When fd refers to the controlling terminal of the calling process, the function tcgetp‐
grp() 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. When fd does
not refer to the controlling terminal of the calling process, -1 is returned, and errno is
set appropriately.
When successful, tcsetpgrp() returns 0. Otherwise, it returns -1, and errno is set appro‐
priately.
ERRORS
EBADF fd is not a valid file descriptor.
EINVAL pgrp has an unsupported value.
ENOTTY 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.
EPERM pgrp has a supported value, but is not the process group ID of a process in the
same session as the calling process.
ATTRIBUTES
Multithreading (see pthreads(7))
The tcgetpgrp() and tcsetpgrp() functions are thread-safe.
CONFORMING TO
POSIX.1-2001.
NOTES
These functions are implemented via the TIOCGPGRP and TIOCSPGRP ioctls.
History
The ioctls appeared in 4.2BSD. The functions are POSIX inventions.
SEE ALSO
setpgid(2), setsid(2), credentials(7)
COLOPHON
This page is part of release 3.74 of the Linux man-pages project. A description of the
project, information about reporting bugs, and the latest version of this page, can be
found at http://www.kernel.org/doc/man-pages/.
GNU 2014-01-13 TCGETPGRP(3)
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