From abad4f0576a7dc361e5385e19c7681449103cdb1 Mon Sep 17 00:00:00 2001
From: Akim Demaille <akim@epita.fr>
Date: Mon, 22 Jan 2001 08:59:14 +0000
Subject: [PATCH] * doc/autoconf.texi: Some about diff and cmp.

---
 ChangeLog         |  4 ++++
 doc/autoconf.texi | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 042ef12b..04c6d0ab 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2001-01-22  Akim Demaille  <akim@epita.fr>
+
+	* doc/autoconf.texi: Some about diff and cmp.
+
 2001-01-22  Akim Demaille  <akim@epita.fr>
 
 	* sh.m4 (AS_ESCAPE): New.
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 623b6665..abe0ef40 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -6078,6 +6078,16 @@ Don't rely on any option.  The option @option{-v}, which shows
 non printing characters, @emph{seems} portable though.
 
 
+@item @command{cmp}
+@c ----------------
+@cindex @command{cmp}
+@command{cmp} performs a raw data comparison of two files, while
+@command{diff} compares two text files.  Therefore, if you might compare
+DOS files, even if only checking whether two files are different, use
+@command{diff} to avoid spurious differences due to differences of
+newline encoding.
+
+
 @item @command{cp}
 @c ---------------
 @cindex @command{cp}
@@ -6097,6 +6107,14 @@ newer systems, @code{rename}).
 @c without -r???
 
 
+@item @command{diff}
+@c -----------------
+@cindex @command{diff}
+Option @option{-u} is nonportable.
+
+Some implementations, such as Tru64's, fail when comparing to
+@file{/dev/null}.  Use an empty file instead.
+
 @item @command{dirname}
 @c --------------------
 @cindex @command{dirname}