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[PATCH] mergetool: support --tool-help option like difftool does

From
Sebastian Schuberth <sschuberth@gmail.com>
Date
Jul 23, 2012, 18:58 UTC
Message-ID
<500D9EDB.90603@gmail.com>
In-Reply-To
<500D9E5A.2000204@gmail.com>

This way we do not have to risk the list of tools go out of sync between the implementation and the documentation. Adjust the documentation accordingly to not explicitly list the tools but refer to --tool-help.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
---
 Documentation/git-difftool.txt  |  7 ++++---
 Documentation/git-mergetool.txt |  8 ++++----
 git-mergetool--lib.sh           | 11 ++++++++++-
 git-mergetool.sh                | 42 ++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 59 insertions(+), 9 deletions(-)
diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 31fc2e3..0bdfe35 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -36,9 +36,10 @@ OPTIONS
 
 -t <tool>::
 --tool=<tool>::
-	Use the diff tool specified by <tool>.  Valid values include
-	emerge, kompare, meld, and vimdiff. Run `git difftool --tool-help`
-	for the list of valid <tool> settings.
+	Use the diff tool specified by <tool>.
+
+--tool-help::
+	List all supported values for <tool>.
 +
 If a diff tool is not specified, 'git difftool'
 will use the configuration variable `diff.tool`.  If the
diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 2a49de7..99e53b1 100644
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -26,10 +26,10 @@ OPTIONS
 -------
 -t <tool>::
 --tool=<tool>::
-	Use the merge resolution program specified by <tool>.
-	Valid merge tools are:
-	araxis, bc3, diffuse, ecmerge, emerge, gvimdiff, kdiff3,
-	meld, opendiff, p4merge, tkdiff, tortoisemerge, vimdiff and xxdiff.
+	Use the merge tool specified by <tool>.
+
+--tool-help::
+	List all supported values for <tool>.
 +
 If a merge resolution program is not specified, 'git mergetool'
 will use the configuration variable `merge.tool`.  If the
diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index ed630b2..f0865d4 100644
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -111,15 +111,18 @@ run_merge_tool () {
 	return $status
 }
 
-guess_merge_tool () {
+list_merge_tool_candidates () {
+	# Add tools that can either do merging or diffing, but not both.
 	if merge_mode
 	then
 		tools="tortoisemerge"
 	else
 		tools="kompare"
 	fi
+
 	if test -n "$DISPLAY"
 	then
+		# Prefer GTK-based tools under Gnome.
 		if test -n "$GNOME_DESKTOP_SESSION_ID"
 		then
 			tools="meld opendiff kdiff3 tkdiff xxdiff $tools"
@@ -128,6 +131,8 @@ guess_merge_tool () {
 		fi
 		tools="$tools gvimdiff diffuse ecmerge p4merge araxis bc3"
 	fi
+
+	# Prefer vimdiff if vim is the default editor.
 	case "${VISUAL:-$EDITOR}" in
 	*vim*)
 		tools="$tools vimdiff emerge"
@@ -136,6 +141,10 @@ guess_merge_tool () {
 		tools="$tools emerge vimdiff"
 		;;
 	esac
+}
+
+guess_merge_tool () {
+	list_merge_tool_candidates
 	echo >&2 "merge tool candidates: $tools"
 
 	# Loop over each candidate and stop when a valid merge tool is found.
diff --git a/git-mergetool.sh b/git-mergetool.sh
index a9f23f7..0db0c44 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -8,7 +8,7 @@
 # at the discretion of Junio C Hamano.
 #
 
-USAGE='[--tool=tool] [-y|--no-prompt|--prompt] [file to merge] ...'
+USAGE='[--tool=tool] [--tool-help] [-y|--no-prompt|--prompt] [file to merge] ...'
 SUBDIRECTORY_OK=Yes
 OPTIONS_SPEC=
 TOOL_MODE=merge
@@ -284,11 +284,51 @@ merge_file () {
     return 0
 }
 
+show_tool_help () {
+	TOOL_MODE=merge
+	list_merge_tool_candidates
+	unavailable= available= LF='
+'
+	for i in $tools
+	do
+		merge_tool_path=$(translate_merge_tool_path "$i")
+		if type "$merge_tool_path" >/dev/null 2>&1
+		then
+			available="$available$i$LF"
+		else
+			unavailable="$unavailable$i$LF"
+		fi
+	done
+	if test -n "$available"
+	then
+		echo "'git mergetool --tool=<tool>' may be set to one of the following:"
+		echo "$available" | sort | sed -e 's/^/	/'
+	else
+		echo "No suitable tool for 'git mergetool --tool=<tool>' found."
+	fi
+	if test -n "$unavailable"
+	then
+		echo
+		echo 'The following tools are valid, but not currently available:'
+		echo "$unavailable" | sort | sed -e 's/^/	/'
+	fi
+	if test -n "$unavailable$available"
+	then
+		echo
+		echo "Some of the tools listed above only work in a windowed"
+		echo "environment. If run in a terminal-only session, they will fail."
+	fi
+	exit 0
+}
+
 prompt=$(git config --bool mergetool.prompt || echo true)
 
 while test $# != 0
 do
     case "$1" in
+	--tool-help)
+		show_tool_help
+		;;
 	-t|--tool*)
 	    case "$#,$1" in
 		*,*=*)
-- 
1.7.11.msysgit.2
Previous: Sebastian SchuberthNext: Junio C Hamano
Message 14 of 40 in “Various merge / diff tool related minor clean-ups and improvements”
  1. 0/4 Various merge / diff tool related minor clean-ups and improvementsSebastian Schuberth, Jul 23, 2012
  2. 0/5 Various merge / diff tool related minor clean-ups and improvementsSebastian Schuberth, Jul 23, 2012
  3. 1/5 Sort the list of tools that support both merging and diffing alphabeticallySebastian Schuberth, Jul 23, 2012
  4. 2/5 Use variables for the lists of tools that support merging / diffingSebastian Schuberth, Jul 23, 2012
  5. Junio C HamanoJul 23, 2012
  6. Sebastian SchuberthJul 23, 2012
  7. 1/4 Use variables for the lists of tools that support merging / diffingSebastian Schuberth, Jul 23, 2012
  8. Junio C HamanoJul 23, 2012
  9. Sebastian SchuberthJul 23, 2012
  10. 3/5 Explicitly list all valid diff tools and document --tool-help as an optionSebastian Schuberth, Jul 23, 2012
  11. Junio C HamanoJul 23, 2012
  12. mergetool: support --tool-help option like difftool doesJunio C Hamano, Jul 23, 2012
  13. Sebastian SchuberthJul 23, 2012
  14. mergetool: support --tool-help option like difftool doesSebastian Schuberth, Jul 23, 2012
  15. Junio C HamanoJul 23, 2012
  16. Sebastian SchuberthJul 23, 2012
  17. David AguilarJul 23, 2012
  18. Junio C HamanoJul 23, 2012
  19. Sebastian SchuberthJul 23, 2012
  20. Junio C HamanoJul 23, 2012
  21. Re*: mergetool: support --tool-help option like difftool doesJunio C Hamano, Aug 23, 2012
  22. David AguilarAug 23, 2012
  23. Junio C HamanoAug 23, 2012
  24. David AguilarAug 24, 2012
  25. Jens LehmannAug 26, 2012
  26. 4/5 Make sure to use Araxis' "compare" and not e.g. ImageMagick'sSebastian Schuberth, Jul 23, 2012
  27. Junio C HamanoJul 23, 2012
  28. Make sure to use Araxis' "compare" and not e.g. ImageMagick'sSebastian Schuberth, Jul 23, 2012
  29. Junio C HamanoJul 23, 2012
  30. Sebastian SchuberthJul 23, 2012
  31. Junio C HamanoJul 23, 2012
  32. Sebastian SchuberthJul 23, 2012
  33. David AguilarJul 23, 2012
  34. Sebastian SchuberthJul 23, 2012
  35. Andreas SchwabJul 23, 2012
  36. Junio C HamanoJul 23, 2012
  37. Sebastian SchuberthJul 23, 2012
  38. Junio C HamanoJul 23, 2012
  39. Sebastian SchuberthJul 23, 2012
  40. 5/5 Add a few more code comments and blank lines in guess_merge_toolSebastian Schuberth, Jul 23, 2012

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