From dd9b25a6caa24be4f3512ee2b4412e08333a476b Mon Sep 17 00:00:00 2001
From: Michael Kerrisk <mtk.manpages@gmail.com>
Date: Sat, 30 Jun 2007 13:14:42 +0000
Subject: [PATCH] Added an EXAMPLE code segment.

---
 man2/semop.2 | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/man2/semop.2 b/man2/semop.2
index 98ce1d52d..557256f00 100644
--- a/man2/semop.2
+++ b/man2/semop.2
@@ -28,8 +28,9 @@
 .\"	Language and formatting clean-ups
 .\"	Added notes on /proc files
 .\" 2005-04-08, mtk, Noted kernel version numbers for semtimedop()
+.\" 2007-07-09, mtk, Added an EXAMPLE code segment.
 .\"
-.TH SEMOP 2 2004-11-10 "Linux" "Linux Programmer's Manual"
+.TH SEMOP 2 2007-07-09 "Linux" "Linux Programmer's Manual"
 .SH NAME
 semop, semtimedop \- semaphore operations
 .SH SYNOPSIS
@@ -478,6 +479,31 @@ This bug is fixed in kernel 2.6.11.
 .\" http://marc.theaimsgroup.com/?l=linux-kernel&m=110260821123863&w=2
 .\" the fix:
 .\" http://marc.theaimsgroup.com/?l=linux-kernel&m=110261701025794&w=2
+.SH EXAMPLE
+The following code segment uses
+.BR semop ()
+to atomically wait for the value of semaphore 0 to become zero,
+and then increment the semaphore value by one.
+.nf
+
+    struct sembuf sops[2];
+    int semid;
+
+    /* Code to set \fIsemid\fP omitted */
+
+    sops[0].sem_num = 0;        /* Operate on semaphore 0 */
+    sops[0].sem_op = 0;         /* Wait for value to equal 0 */
+    sops[0].sem_flg = 0;
+
+    sops[1].sem_num = 0;        /* Operate on semaphore 0 */
+    sops[1].sem_op = 0;         /* Increment value by one */
+    sops[1].sem_flg = 0;
+
+    if (semop(semid, &sop, 2) == \-1) {
+        perror("semop");
+        exit(EXIT_FAILURE);
+    }
+.fi
 .SH "SEE ALSO"
 .BR semctl (2),
 .BR semget (2),