Section: POSIX Programmer's Manual (3P)
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
--- set the foreground process group ID
int tcsetpgrp(int fildes, pid_t pgid_id);
If the process has a controlling terminal,
shall set the foreground process group ID associated with the terminal
The application shall ensure that the file associated with
is the controlling terminal of the calling process and the controlling
terminal is currently associated with the session of the calling
process. The application shall ensure that the value of
matches a process group ID of a process in the same session as the
Attempts to use
from a process which is a member of a background process group on a
associated with its controlling terminal shall cause the process group
to be sent a SIGTTOU signal. If the calling thread is blocking SIGTTOU
signals or the process is ignoring SIGTTOU signals, the process shall
be allowed to perform the operation, and no signal is sent.
Upon successful completion, 0 shall be returned. Otherwise, -1
shall be returned and
set to indicate the error.
function shall fail if:
argument is not a valid file descriptor.
This implementation does not support the value in the
The process group of the writing process is orphaned, the calling thread
is not blocking SIGTTOU, and the process is not ignoring SIGTTOU.
The calling process does not have a controlling terminal, or the file
is not the controlling terminal, or the controlling terminal is no
longer associated with the session of the calling process.
The value of
is a value supported by the implementation, but does not match the
process group ID of a process in the same session as the calling
The following sections are informative.
The Base Definitions volume of POSIX.1-2017,
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
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