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.TH TCSETPGRP "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"
.SH PROLOG
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.

.SH NAME
tcsetpgrp
\(em set the foreground process group ID
.SH SYNOPSIS
.LP
.nf
#include <unistd.h>
.P
int tcsetpgrp(int \fIfildes\fP, pid_t \fIpgid_id\fP);
.fi
.SH DESCRIPTION
If the process has a controlling terminal,
\fItcsetpgrp\fR()
shall set the foreground process group ID associated with the terminal
to
.IR pgid_id .
The application shall ensure that the file associated with
.IR fildes
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
.IR pgid_id
matches a process group ID of a process in the same session as the
calling process.
.P
Attempts to use
\fItcsetpgrp\fR()
from a process which is a member of a background process group on a
.IR fildes
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.
.SH "RETURN VALUE"
Upon successful completion, 0 shall be returned. Otherwise, \(mi1
shall be returned and
.IR errno
set to indicate the error.
.SH ERRORS
The
\fItcsetpgrp\fR()
function shall fail if:
.TP
.BR EBADF
The
.IR fildes
argument is not a valid file descriptor.
.TP
.BR EINVAL
This implementation does not support the value in the
.IR pgid_id
argument.
.TP
.BR EIO
The process group of the writing process is orphaned, the calling thread
is not blocking SIGTTOU, and the process is not ignoring SIGTTOU.
.TP
.BR ENOTTY
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.
.TP
.BR EPERM
The value of
.IR pgid_id
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
process.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fItcgetpgrp\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2008,
.IR "\fB<sys_types.h>\fP",
.IR "\fB<unistd.h>\fP"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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
http://www.unix.org/online.html .

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