From c2a205a8e12f3daaeb7fd1c92ad862999ae630dc Mon Sep 17 00:00:00 2001
From: Werner LEMBERG <wl@gnu.org>
Date: Mon, 13 Dec 2004 20:53:26 +0000
Subject: [PATCH] Add `-x' command line option to select a diff program.

* gdiffmk.sh: Add code to handle `-x'.
Move test for working `diff' down.
Fix sed pattern.
(Usage): Updated.
* gdiffmk.man: Updated.
---
 contrib/gdiffmk/ChangeLog   | 10 ++++++++++
 contrib/gdiffmk/gdiffmk.man | 24 +++++++++++++++++++++++-
 contrib/gdiffmk/gdiffmk.sh  | 44 +++++++++++++++++++++++++-------------------
 3 files changed, 58 insertions(+), 20 deletions(-)

diff --git a/contrib/gdiffmk/ChangeLog b/contrib/gdiffmk/ChangeLog
index 15d73788..a461b440 100644
--- a/contrib/gdiffmk/ChangeLog
+++ b/contrib/gdiffmk/ChangeLog
@@ -1,3 +1,13 @@
+2004-12-13  Mike Bianchi  <MBianchi@Foveal.com>
+
+	Add `-x' command line option to select a diff program.
+
+	* gdiffmk.sh: Add code to handle `-x'.
+	Move test for working `diff' down.
+	Fix sed pattern.
+	(Usage): Updated.
+	* gdiffmk.man: Updated.
+
 2004-12-12  Mike Bianchi  <MBianchi@Foveal.com>
 
 	* README: New file.
diff --git a/contrib/gdiffmk/gdiffmk.man b/contrib/gdiffmk/gdiffmk.man
index 94d75e97..19bf40d1 100644
--- a/contrib/gdiffmk/gdiffmk.man
+++ b/contrib/gdiffmk/gdiffmk.man
@@ -43,6 +43,7 @@ gdiffmk \- mark differences between groff/nroff/troff files
 .OP \-a \%addmark
 .OP \-c \%changemark
 .OP \-d \%deletemark
+.OP \-x \%diffcmd
 .OP \-\-
 .OP \-\-help
 .OP \-\-version
@@ -51,6 +52,8 @@ gdiffmk \- mark differences between groff/nroff/troff files
 [
 .I \%output
 ]
+.br
+.ad \na
 .
 .
 .SH DESCRIPTION
@@ -125,6 +128,22 @@ Default:
 .BR * .
 .
 .TP
+.BI \-x diffcmd
+Use the
+.I diffcmd
+command to perform the comparison of
+.I file1
+and
+.I file2 .
+In particular,
+.I diffcmd
+should accept the
+.BI \-D name
+option.
+Default:
+.BR diff (1).
+.
+.TP
 .B \-\-
 All the following arguments are treated as file names,
 even if they begin with
@@ -150,13 +169,16 @@ on the output of all the preprocessors instead of the input source.
 .LP
 .B gdiffmk
 relies on the
-.B \-D
+.BI \-D name
 option of GNU
 .BR diff (1)
 to make a merged `#ifdef' output format.
 It hasn't been tested whether other versions of
 .BR diff (1)
 do support this option.
+See also the
+.BI \-x diffcmd
+option.
 .
 .LP
 Report bugs to bug-groff@gnu.org.
diff --git a/contrib/gdiffmk/gdiffmk.sh b/contrib/gdiffmk/gdiffmk.sh
index a2ffcfac..87bc9c36 100644
--- a/contrib/gdiffmk/gdiffmk.sh
+++ b/contrib/gdiffmk/gdiffmk.sh
@@ -23,16 +23,6 @@
 
 cmd=$( basename $0 )
 
-diff -Dx /dev/null /dev/null >/dev/null 2>&1  ||
-	{
-		echo >&2 "${cmd}:  "				\
-			"The \`diff' program does not accept "	\
-			"the required -DNAME option."
-		echo >&2 "${cmd}:  "				\
-			"Use GNU diff instead."
-		exit 126
-	}
-
 function Usage {
 	if test "$#" -gt 0
 	then
@@ -51,12 +41,14 @@ groff \`.mc' requests added to indicate how it is different from FILE1.
   OUTPUT  Copy of FILE2 with \`.mc' commands added.
           \`-' means standard output (the default).
 
-options:
+OPTIONS:
   -a addmark     Mark for added groff source lines.    Default: +.
   -c changemark  Mark for changed groff source lines.  Default: |.
   -d deletemark  Mark for deleted groff source lines.  Default: *.
-  --version      Print version information on standard output and exit.
-  --help         Print this message on standard error.
+  -x diffcmd     Use a different diff(1) command;
+  	          one that accepts the \`-Dname' option, such as GNU diff.
+  --version      Print version information on the standard output and exit.
+  --help         Print this message on the standard error.
 "
 	exit 255
 }
@@ -150,19 +142,24 @@ function RequiresArgument {
 }
 
 badoption=
-for option
+diffcmd=diff
+for OPTION
 do
-	case "${option}" in
+	case "${OPTION}" in
 	-a*)
-		addmark=$( RequiresArgument "${option}" $2 )		&&
+		addmark=$( RequiresArgument "${OPTION}" $2 )		&&
 			shift
 		;;
 	-c*)
-		changemark=$( RequiresArgument "${option}" $2 )		&&
+		changemark=$( RequiresArgument "${OPTION}" $2 )		&&
 			shift
 		;;
 	-d*)
-		deletemark=$( RequiresArgument "${option}" $2 )		&&
+		deletemark=$( RequiresArgument "${OPTION}" $2 )		&&
+			shift
+		;;
+	-x* )
+		diffcmd=$( RequiresArgument "${OPTION}" $2 )		&&
 			shift
 		;;
 	--version)
@@ -190,6 +187,11 @@ do
 	shift
 done
 
+${diffcmd} -Dx /dev/null /dev/null >/dev/null 2>&1  ||
+	Usage "The \`${diffcmd}' program does not accept"	\
+		"the required \`-Dname' option.
+Use GNU diff instead.  See the \`-x diffcmd' option."
+
 if test -n "${badoption}"
 then
 	Usage "${badoption}"
@@ -246,7 +248,11 @@ diff -D"${label}" -- ${FILE1} ${FILE2}  |
 		    p
 		    d
 		  }
-		  /^#endif \/\* not '"${label}"'/ s/.*/.mc '"${deletemark}"'/p
+		  /^#endif \/\* not '"${label}"'/ {
+		   s/.*/.mc '"${deletemark}"'/p
+		   a\
+.mc
+		  }
 		  d
 		}
 		p
-- 
2.11.4.GIT