1 files changed, 126 insertions, 0 deletions
diff --git a/man3/tcgetpgrp.3 b/man3/tcgetpgrp.3
new file mode 100644
index 0000000..494ed43
--- /dev/null
+++ b/man3/tcgetpgrp.3
@@ -0,0 +1,126 @@
+'\" t
+.\" Copyright (C) 2002 Andries Brouwer <aeb@cwi.nl>
+.\"
+.\" SPDX-License-Identifier: Linux-man-pages-copyleft
+.\"
+.TH tcgetpgrp 3 2023-07-20 "Linux man-pages 6.05.01"
+.SH NAME
+tcgetpgrp, tcsetpgrp \- get and set terminal foreground process group
+.SH LIBRARY
+Standard C library
+.RI ( libc ", " \-lc )
+.SH SYNOPSIS
+.nf
+.B "#include <unistd.h>"
+.PP
+.BI "pid_t tcgetpgrp(int " fd );
+.BI "int tcsetpgrp(int " fd ", pid_t " pgrp );
+.fi
+.SH DESCRIPTION
+The function
+.BR tcgetpgrp ()
+returns the process group ID of the foreground process group on the
+terminal associated to
+.IR fd ,
+which must be the controlling terminal of the calling process.
+.\" The process itself may be a background process.
+.PP
+The function
+.BR tcsetpgrp ()
+makes the process group with process group ID
+.I pgrp
+the foreground process group on the terminal associated to
+.IR fd ,
+which must be the controlling terminal of the calling process,
+and still be associated with its session.
+Moreover,
+.I pgrp
+must be a (nonempty) process group belonging to
+the same session as the calling process.
+.PP
+If
+.BR tcsetpgrp ()
+is called by a member of a background process group in its session,
+and the calling process is not blocking or ignoring
+.BR SIGTTOU ,
+a
+.B SIGTTOU
+signal is sent to all members of this background process group.
+.SH RETURN VALUE
+When
+.I fd
+refers to the controlling terminal of the calling process,
+the function
+.BR 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
+.I fd
+does not refer to the controlling terminal of the calling process,
+\-1 is returned, and
+.I errno
+is set to indicate the error.
+.PP
+When successful,
+.BR tcsetpgrp ()
+returns 0.
+Otherwise, it returns \-1, and
+.I errno
+is set to indicate the error.
+.SH ERRORS
+.TP
+.B EBADF
+.I fd
+is not a valid file descriptor.
+.TP
+.B EINVAL
+.I pgrp
+has an unsupported value.
+.TP
+.B ENOTTY
+The calling process does not have a controlling terminal, or
+it has one but it is not described by
+.IR fd ,
+or, for
+.BR tcsetpgrp (),
+this controlling terminal is no longer associated with the session
+of the calling process.
+.TP
+.B EPERM
+.I pgrp
+has a supported value, but is not the process group ID of a
+process in the same session as the calling process.
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lbx lb lb
+l l l.
+Interface	Attribute	Value
+T{
+.na
+.nh
+.BR tcgetpgrp (),
+.BR tcsetpgrp ()
+T}	Thread safety	MT-Safe
+.TE
+.sp 1
+.SH VERSIONS
+These functions are implemented via the
+.B TIOCGPGRP
+and
+.B TIOCSPGRP
+ioctls.
+.SH STANDARDS
+POSIX.1-2008.
+.SH HISTORY
+POSIX.1-2001.
+.PP
+The ioctls appeared in 4.2BSD.
+The functions are POSIX inventions.
+.SH SEE ALSO
+.BR setpgid (2),
+.BR setsid (2),
+.BR credentials (7)