From bdfea496cf9f32b9fcfa8be83ee37931138e6ea1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fernando=20Apestegu=C3=ADa?= <fernape@FreeBSD.org>
Date: Mon, 27 Jul 2020 16:51:23 +0000
Subject: [PATCH] comm(1): Add EXAMPLES section

Add two very simple examples.

Approved by:	manpages (gbe@)
Differential Revision: https://reviews.freebsd.org/D25344
---
 usr.bin/comm/comm.1 | 35 +++++++++++++++++++++++++++++++----
 1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/usr.bin/comm/comm.1 b/usr.bin/comm/comm.1
index 6e258806287e..b70e08692bd6 100644
--- a/usr.bin/comm/comm.1
+++ b/usr.bin/comm/comm.1
@@ -31,7 +31,7 @@
 .\"     From: @(#)comm.1	8.1 (Berkeley) 6/6/93
 .\" $FreeBSD$
 .\"
-.Dd December 12, 2009
+.Dd July 27, 2020
 .Dt COMM 1
 .Os
 .Sh NAME
@@ -95,6 +95,35 @@ as described in
 .Xr environ 7 .
 .Sh EXIT STATUS
 .Ex -std
+.Sh EXAMPLES
+Assuming a file named
+.Pa example.txt
+with the following contents:
+.Bd -literal -offset indent
+a
+b
+c
+d
+.Ed
+.Pp
+Show lines only in
+.Pa example.txt ,
+lines only in stdin and common lines:
+.Bd -literal -offset indent
+$ echo -e "B\enc" | comm example.txt -
+        B
+a
+b
+                c
+d
+.Ed
+.Pp
+Show only common lines doing case insensitive comparisons:
+.Bd -literal -offset indent
+$ echo -e "B\enc" | comm -1 -2 -i example.txt -
+b
+c
+.Ed
 .Sh SEE ALSO
 .Xr cmp 1 ,
 .Xr diff 1 ,
@@ -108,9 +137,7 @@ utility conforms to
 .Pp
 The
 .Fl i
-option is an extension to the
-.Tn POSIX
-standard.
+option is an extension to the POSIX standard.
 .Sh HISTORY
 A
 .Nm