3 files changed, 118 insertions, 3 deletions
diff --git a/lib/libc/termios/Makefile.inc b/lib/libc/termios/Makefile.inc
index 14002b3d3bc..23fa56e0179 100644
--- a/lib/libc/termios/Makefile.inc
+++ b/lib/libc/termios/Makefile.inc
@@ -1,12 +1,12 @@
-#	$OpenBSD: Makefile.inc,v 1.3 1998/11/20 11:18:54 d Exp $
+#	$OpenBSD: Makefile.inc,v 1.4 2013/12/17 16:31:36 millert Exp $
 
 .PATH:	${LIBCSRCDIR}/termios
 
 SRCS+=	cfgetispeed.c cfgetospeed.c cfmakeraw.c cfsetispeed.c cfsetospeed.c \
 	cfsetspeed.c tcdrain.c tcflow.c tcflush.c tcgetattr.c tcgetpgrp.c \
-	tcsendbreak.c tcsetattr.c tcsetpgrp.c
+	tcsendbreak.c tcsetattr.c tcsetpgrp.c tcgetsid.c
 
-MAN+=	tcgetpgrp.3 tcsendbreak.3 tcsetattr.3 tcsetpgrp.3
+MAN+=	tcgetpgrp.3 tcsendbreak.3 tcsetattr.3 tcsetpgrp.3 tcgetsid.3
 
 MLINKS+=tcsendbreak.3 tcdrain.3 tcsendbreak.3 tcflow.3 \
 	tcsendbreak.3 tcflush.3
diff --git a/lib/libc/termios/tcgetsid.3 b/lib/libc/termios/tcgetsid.3
new file mode 100644
index 00000000000..a5206c90d6f
--- /dev/null
+++ b/lib/libc/termios/tcgetsid.3
@@ -0,0 +1,72 @@
+.\"	$OpenBSD: tcgetsid.3,v 1.1 2013/12/17 16:31:36 millert Exp $
+.\"
+.\" Copyright (c) 1991 The Regents of the University of California.
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.Dd $Mdocdate: December 17 2013 $
+.Dt TCGETSID 3
+.Os
+.Sh NAME
+.Nm tcgetsid
+.Nd get session ID associated with a controlling terminal
+.Sh SYNOPSIS
+.In termios.h
+.Ft pid_t
+.Fn tcgetsid "int fd"
+.Sh DESCRIPTION
+The
+.Fn tcgetsid
+function returns the value of the session ID associated with the specified
+controlling terminal device.
+The session ID is defined as the process group ID of the session leader.
+.Sh ERRORS
+If an error occurs,
+.Fn tcgetsid
+returns \-1 and the global variable
+.Va errno
+is set to indicate the error, as follows:
+.Bl -tag -width Er
+.It Bq Er EBADF
+The
+.Fa fd
+argument is not a valid file descriptor.
+.It Bq Er ENOTTY
+The calling process does not have a controlling terminal or the
+underlying terminal device represented by
+.Fa fd
+is not the controlling terminal.
+.El
+.Sh SEE ALSO
+.Xr getsid 2 ,
+.Xr setsid 2 ,
+.Xr tcgetpgrp 3
+.Sh STANDARDS
+The
+.Fn tcgetsid
+function is expected to be compliant with the
+.St -p1003.1-2008
+specification.
diff --git a/lib/libc/termios/tcgetsid.c b/lib/libc/termios/tcgetsid.c
new file mode 100644
index 00000000000..52278b0c6ba
--- /dev/null
+++ b/lib/libc/termios/tcgetsid.c
@@ -0,0 +1,43 @@
+/*	$OpenBSD: tcgetsid.c,v 1.1 2013/12/17 16:31:36 millert Exp $ */
+/*-
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/ioctl.h>
+#include <termios.h>
+
+pid_t
+tcgetsid(int fd)
+{
+	int s;
+
+	if (ioctl(fd, TIOCGSID, &s) < 0)
+		return ((pid_t)-1);
+
+	return ((pid_t)s);
+}