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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
TCGETPGRP(3) Linux Programmer's Manual TCGETPGRP(3)
tcgetpgrp, tcsetpgrp - get and set terminal foreground process group
#include <unistd.h>
pid_t tcgetpgrp(int fd);
int tcsetpgrp(int fd, pid_t pgrp);
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 members of this background
process group.
When 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. 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 appropriately.
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.
For an explanation of the terms used in this section, see
attributes(7).
┌─────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├─────────────────────────┼───────────────┼─────────┤
│tcgetpgrp(), tcsetpgrp() │ Thread safety │ MT-Safe │
└─────────────────────────┴───────────────┴─────────┘
POSIX.1-2001, POSIX.1-2008.
These functions are implemented via the TIOCGPGRP and TIOCSPGRP
ioctls.
History
The ioctls appeared in 4.2BSD. The functions are POSIX inventions.
setpgid(2), setsid(2), credentials(7)
This page is part of release 4.12 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
https://www.kernel.org/doc/man-pages/.
GNU 2015-08-08 TCGETPGRP(3)
Pages that refer to this page: setpgid(2), credentials(7), signal-safety(7)