ediff: learn --merge, and gain an optional REGEX filter for --recursive

This brings it much closer to being a complete interface to ediff on files.

2 files changed, 61 insertions, 12 deletions

diff --git a/common.sh.in b/common.sh.in
index 2488a69..54431fe 100644
--- a/common.sh.in
+++ b/common.sh.in
@@ -1,6 +1,6 @@
 # begin common.sh {{{
 
-# Copyright (C) 2013-2014, 2016 Luke Shumaker <lukeshu@sbcglobal.net>
+# Copyright (C) 2013-2014, 2016-2017 Luke Shumaker <lukeshu@sbcglobal.net>
 #
 # This file is not considered part of GNU Emacs.
 #
@@ -42,7 +42,9 @@ flag() {
 		printf -- "%s\n" "$flag"
 		flag=''
 	fi
-	printf -- "%- ${_flag_indent}s%s\n" "$flag" "$(print "${@:2}")"
+	local text
+	text="$(print "${@:2}")"
+	printf -- "%- ${_flag_indent}s%s\n" "$flag" "${text//$'\n'/"$(printf -- "\n%- ${_flag_indent}s%s\n" '')"}"
 }
 
 error() {
diff --git a/ediff.sh.in b/ediff.sh.in
index 569721e..1a227bb 100644
--- a/ediff.sh.in
+++ b/ediff.sh.in
@@ -1,6 +1,6 @@
 #!@bash@
 
-# Copyright (C) 2014, 2016 Luke Shumaker <lukeshu@sbcglobal.net>
+# Copyright (C) 2014, 2016-2017 Luke Shumaker <lukeshu@sbcglobal.net>
 #
 # This file is not considered part of GNU Emacs.
 #
@@ -21,25 +21,56 @@ m4_include(common.sh.in)
 
 usage() {
 	print 'Usage: %q [OPTIONS] FILE_A FILE_B' "$0"
-	print '   or: %q -3 [OPTIONS] FILE_A FILE_B FILE_C' "$0"
+	print '   or: %q -3 [OPTIONS] FILE_A FILE_B FILE_C|FILE_ANCESTOR' "$0"
 	print "Use Emacs' ediff-mode to compare two files"
 	echo
 	print 'The following OPTIONS are accepted:'
 	emacs_usage
-	flag '-3' 'Do a 3-way diff instead of 2-way'
-	flag '-r, --recursive' 'Diff directories recursively'
+	flag '-r, -R REGEXP, --recursive[=REGEXP]' \
+	     'Diff directories recursively,
+excluding filenames not matching REGEXP'
+
+	flag '-3' \
+	     'Do a 3-way diff instead of 2-way
+When used in the context of a --merge,
+the 3rd file is the common ancestor between A and B'
+
+	flag '-m OUTFILE, --merge=OUTFILE' \
+	     'Merge files A and B, saving the output in OUTFILE'
 }
 
 main() {
 	declare -a flags=()
-	declare -a files=()
-	declare -i cnt=2
-	declare cmd=ediff
 	declare mode=normal
 
+	# The functions that we currently make available are:
+	#   (ediff                     FILE-A FILE-B               &optional STARTUP-HOOKS)
+	#   (ediff3                    FILE-A FILE-B FILE-C        &optional STARTUP-HOOKS)
+	#   (ediff-merge               FILE-A FILE-B               &optional STARTUP-HOOKS MERGE-BUFFER-FILE)
+	#   (ediff-merge-with-ancestor FILE-A FILE-B FILE-ANCESTOR &optional STARTUP-HOOKS MERGE-BUFFER-FILE)
+	# and their recursive equivalents:
+	#   (edirs                     DIR1 DIR2              REGEXP)
+	#   (edirs3                    DIR1 DIR2 DIR3         REGEXP)
+	#   (edirs-merge               DIR1 DIR2              REGEXP &optional MERGE-AUTOSTORE-DIR)
+	#   (edirs-merge-with-ancestor DIR1 DIR2 ANCESTOR-DIR REGEXP &optional MERGE-AUTOSTORE-DIR)
+	#
+	# This list is currently missing the "revision" commands:
+	#   (ediff-revision &optional FILE STARTUP-HOOKS)
+	#   (edir-revisions                     DIR1 REGEXP)
+	#   (edir-merge-revisions               DIR1 REGEXP &optional MERGE-AUTOSTORE-DIR)
+	#   (edir-merge-revisions-with-ancestor DIR1 REGEXP &optional MERGE-AUTOSTORE-DIR)
+	# and the epatch command:
+	#   (epatch &optional ARG PATCH-BUF)
+
+	declare cmd=ediff
+	declare -i cnt=2
+	declare -a files=()
+	declare extra=nil # STARTUP-HOOKS for cmd=ediff, REGEXP for cmd=edirs
+	declare merge=''
+
 	emacs_getopt_init
 	declare args
-	if ! args="$(emacs_getopt 3r recursive "$@")"; then
+	if ! args="$(emacs_getopt rR:3m: recursive::,merge: "$@")"; then
 		mode=error
 	else
 		eval set -- "$args"
@@ -47,8 +78,18 @@ main() {
 			case "$1" in
 				-V|--version) shift; mode=version;;
 				-H|--help) shift; mode=usage;;
-				-r|--recursive) shift; cmd=edirs;;
+
+				-r) shift; cmd=edirs;;
+				-R|--recursive)
+					cmd=edirs
+					[[ -z "$2" ]] || extra="$(emacs_quote "$2")"
+					shift 2
+					;;
+
 				-3) shift; cnt=3;;
+
+				-m|--merge) merge="$(emacs_quote "$2")"; shift 2;;
+
 				--) shift; break;;
 				*)
 					if [[ $1 =~ $emacs_getopt_2 ]]; then
@@ -65,9 +106,15 @@ main() {
 		fi
 	fi
 
+	if [[ -z "$merge" ]]; then
+		[[ $cnt == 2 ]] || cmd+='3'
+	else
+		cmd+='-merge'
+		[[ $cnt == 2 ]] || cmd+='-with-ancestor'
+	fi
 	next "$mode" \
 	     emacsclient "${flags[@]}" --eval \
-	     "(${cmd}${cnt#2} $(emacs_quote "${files[@]}"))"
+	     "(${cmd} $(emacs_quote "${files[@]}") $extra $merge)"
 }
 
 main "$@"