contrib: add 'git difftool' for launching common merge tools

'git difftool' is a git command that allows you to compare and edit files
between revisions using common merge tools.  'git difftool' does what
'git mergetool' does but its use is for non-merge situations such as
when preparing commits or comparing changes against the index.
It uses the same configuration variables as 'git mergetool' and
provides the same command-line interface as 'git diff'.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
David Aguilar 2009-01-16 00:00:02 -08:00 committed by Junio C Hamano
parent 3d279863de
commit 5c38ea31f3
3 changed files with 418 additions and 0 deletions

74
contrib/difftool/git-difftool Executable file
View file

@ -0,0 +1,74 @@
#!/usr/bin/env perl
# Copyright (c) 2009 David Aguilar
#
# This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
# git-difftool-helper script. This script exports
# GIT_EXTERNAL_DIFF and GIT_PAGER for use by git, and
# GIT_NO_PROMPT and GIT_MERGE_TOOL for use by git-difftool-helper.
# Any arguments that are unknown to this script are forwarded to 'git diff'.
use strict;
use warnings;
use Cwd qw(abs_path);
use File::Basename qw(dirname);
my $DIR = abs_path(dirname($0));
sub usage
{
print << 'USAGE';
usage: git difftool [--no-prompt] [--tool=tool] ["git diff" options]
USAGE
exit 1;
}
sub setup_environment
{
$ENV{PATH} = "$DIR:$ENV{PATH}";
$ENV{GIT_PAGER} = '';
$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool-helper';
}
sub exe
{
my $exe = shift;
return defined $ENV{COMSPEC} ? "$exe.exe" : $exe;
}
sub generate_command
{
my @command = (exe('git'), 'diff');
my $skip_next = 0;
my $idx = -1;
for my $arg (@ARGV) {
$idx++;
if ($skip_next) {
$skip_next = 0;
next;
}
if ($arg eq '-t' or $arg eq '--tool') {
usage() if $#ARGV <= $idx;
$ENV{GIT_MERGE_TOOL} = $ARGV[$idx + 1];
$skip_next = 1;
next;
}
if ($arg =~ /^--tool=/) {
$ENV{GIT_MERGE_TOOL} = substr($arg, 7);
next;
}
if ($arg eq '--no-prompt') {
$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
next;
}
if ($arg eq '-h' or $arg eq '--help') {
usage();
}
push @command, $arg;
}
return @command
}
setup_environment();
exec(generate_command());

View file

@ -0,0 +1,240 @@
#!/bin/sh
# git-difftool-helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
# It supports kdiff3, tkdiff, xxdiff, meld, opendiff, emerge, ecmerge,
# vimdiff, gvimdiff, and custom user-configurable tools.
# This script is typically launched by using the 'git difftool'
# convenience command.
#
# Copyright (c) 2009 David Aguilar
# Set GIT_DIFFTOOL_NO_PROMPT to bypass the per-file prompt.
should_prompt () {
! test -n "$GIT_DIFFTOOL_NO_PROMPT"
}
# Should we keep the backup .orig file?
keep_backup_mode="$(git config --bool merge.keepBackup || echo true)"
keep_backup () {
test "$keep_backup_mode" = "true"
}
# This function manages the backup .orig file.
# A backup $MERGED.orig file is created if changes are detected.
cleanup_temp_files () {
if test -n "$MERGED"; then
if keep_backup && test "$MERGED" -nt "$BACKUP"; then
test -f "$BACKUP" && mv -- "$BACKUP" "$MERGED.orig"
else
rm -f -- "$BACKUP"
fi
fi
}
# This is called when users Ctrl-C out of git-difftool-helper
sigint_handler () {
echo
cleanup_temp_files
exit 1
}
# This function prepares temporary files and launches the appropriate
# merge tool.
launch_merge_tool () {
# Merged is the filename as it appears in the work tree
# Local is the contents of a/filename
# Remote is the contents of b/filename
# Custom merge tool commands might use $BASE so we provide it
MERGED="$1"
LOCAL="$2"
REMOTE="$3"
BASE="$1"
ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
BACKUP="$MERGED.BACKUP.$ext"
# Create and ensure that we clean up $BACKUP
test -f "$MERGED" && cp -- "$MERGED" "$BACKUP"
trap sigint_handler SIGINT
# $LOCAL and $REMOTE are temporary files so prompt
# the user with the real $MERGED name before launching $merge_tool.
if should_prompt; then
printf "\nViewing: '$MERGED'\n"
printf "Hit return to launch '%s': " "$merge_tool"
read ans
fi
# Run the appropriate merge tool command
case "$merge_tool" in
kdiff3)
basename=$(basename "$MERGED")
"$merge_tool_path" --auto \
--L1 "$basename (A)" \
--L2 "$basename (B)" \
-o "$MERGED" "$LOCAL" "$REMOTE" \
> /dev/null 2>&1
;;
tkdiff)
"$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
;;
meld|vimdiff)
"$merge_tool_path" "$LOCAL" "$REMOTE"
;;
gvimdiff)
"$merge_tool_path" -f "$LOCAL" "$REMOTE"
;;
xxdiff)
"$merge_tool_path" \
-X \
-R 'Accel.SaveAsMerged: "Ctrl-S"' \
-R 'Accel.Search: "Ctrl+F"' \
-R 'Accel.SearchForward: "Ctrl-G"' \
--merged-file "$MERGED" \
"$LOCAL" "$REMOTE"
;;
opendiff)
"$merge_tool_path" "$LOCAL" "$REMOTE" \
-merge "$MERGED" | cat
;;
ecmerge)
"$merge_tool_path" "$LOCAL" "$REMOTE" \
--default --mode=merge2 --to="$MERGED"
;;
emerge)
"$merge_tool_path" -f emerge-files-command \
"$LOCAL" "$REMOTE" "$(basename "$MERGED")"
;;
*)
if test -n "$merge_tool_cmd"; then
( eval $merge_tool_cmd )
fi
;;
esac
cleanup_temp_files
}
# Verifies that mergetool.<tool>.cmd exists
valid_custom_tool() {
merge_tool_cmd="$(git config mergetool.$1.cmd)"
test -n "$merge_tool_cmd"
}
# Verifies that the chosen merge tool is properly setup.
# Built-in merge tools are always valid.
valid_tool() {
case "$1" in
kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
;; # happy
*)
if ! valid_custom_tool "$1"
then
return 1
fi
;;
esac
}
# Sets up the merge_tool_path variable.
# This handles the mergetool.<tool>.path configuration.
init_merge_tool_path() {
merge_tool_path=$(git config mergetool."$1".path)
if test -z "$merge_tool_path"; then
case "$1" in
emerge)
merge_tool_path=emacs
;;
*)
merge_tool_path="$1"
;;
esac
fi
}
# Allow the GIT_MERGE_TOOL variable to provide a default value
test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
# If not merge tool was specified then use the merge.tool
# configuration variable. If that's invalid then reset merge_tool.
if test -z "$merge_tool"; then
merge_tool=$(git config merge.tool)
if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
echo >&2 "git config option merge.tool set to unknown tool: $merge_tool"
echo >&2 "Resetting to default..."
unset merge_tool
fi
fi
# Try to guess an appropriate merge tool if no tool has been set.
if test -z "$merge_tool"; then
# We have a $DISPLAY so try some common UNIX merge tools
if test -n "$DISPLAY"; then
merge_tool_candidates="kdiff3 tkdiff xxdiff meld gvimdiff"
# If gnome then prefer meld
if test -n "$GNOME_DESKTOP_SESSION_ID"; then
merge_tool_candidates="meld $merge_tool_candidates"
fi
# If KDE then prefer kdiff3
if test "$KDE_FULL_SESSION" = "true"; then
merge_tool_candidates="kdiff3 $merge_tool_candidates"
fi
fi
# $EDITOR is emacs so add emerge as a candidate
if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
merge_tool_candidates="$merge_tool_candidates emerge"
fi
# $EDITOR is vim so add vimdiff as a candidate
if echo "${VISUAL:-$EDITOR}" | grep 'vim' > /dev/null 2>&1; then
merge_tool_candidates="$merge_tool_candidates vimdiff"
fi
merge_tool_candidates="$merge_tool_candidates opendiff emerge vimdiff"
echo "merge tool candidates: $merge_tool_candidates"
# Loop over each candidate and stop when a valid merge tool is found.
for i in $merge_tool_candidates
do
init_merge_tool_path $i
if type "$merge_tool_path" > /dev/null 2>&1; then
merge_tool=$i
break
fi
done
if test -z "$merge_tool" ; then
echo "No known merge resolution program available."
exit 1
fi
else
# A merge tool has been set, so verify that it's valid.
if ! valid_tool "$merge_tool"; then
echo >&2 "Unknown merge tool $merge_tool"
exit 1
fi
init_merge_tool_path "$merge_tool"
if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
echo "The merge tool $merge_tool is not available as '$merge_tool_path'"
exit 1
fi
fi
# Launch the merge tool on each path provided by 'git diff'
while test $# -gt 6
do
launch_merge_tool "$1" "$2" "$5"
shift 7
done

View file

@ -0,0 +1,104 @@
git-difftool(1)
===============
NAME
----
git-difftool - compare changes using common merge tools
SYNOPSIS
--------
'git difftool' [--tool=<tool>] [--no-prompt] ['git diff' options]
DESCRIPTION
-----------
'git difftool' is a git command that allows you to compare and edit files
between revisions using common merge tools. At its most basic level,
'git difftool' does what 'git mergetool' does but its use is for non-merge
situations such as when preparing commits or comparing changes against
the index.
'git difftool' is a frontend to 'git diff' and accepts the same
arguments and options.
See linkgit:git-diff[7] for the full list of supported options.
OPTIONS
-------
-t <tool>::
--tool=<tool>::
Use the merge resolution program specified by <tool>.
Valid merge tools are:
kdiff3, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff, ecmerge, and opendiff
+
If a merge resolution program is not specified, 'git difftool'
will use the configuration variable `merge.tool`. If the
configuration variable `merge.tool` is not set, 'git difftool'
will pick a suitable default.
+
You can explicitly provide a full path to the tool by setting the
configuration variable `mergetool.<tool>.path`. For example, you
can configure the absolute path to kdiff3 by setting
`mergetool.kdiff3.path`. Otherwise, 'git difftool' assumes the
tool is available in PATH.
+
Instead of running one of the known merge tool programs,
'git difftool' can be customized to run an alternative program
by specifying the command line to invoke in a configuration
variable `mergetool.<tool>.cmd`.
+
When 'git difftool' is invoked with this tool (either through the
`-t` or `--tool` option or the `merge.tool` configuration variable)
the configured command line will be invoked with the following
variables available: `$LOCAL` is set to the name of the temporary
file containing the contents of the diff pre-image and `$REMOTE`
is set to the name of the temporary file containing the contents
of the diff post-image. `$BASE` is provided for compatibility
with custom merge tool commands and has the same value as `$LOCAL`.
--no-prompt::
Do not prompt before launching a merge tool.
CONFIG VARIABLES
----------------
merge.tool::
The default merge tool to use.
+
See the `--tool=<tool>` option above for more details.
merge.keepBackup::
The original, unedited file content can be saved to a file with
a `.orig` extension. Defaults to `true` (i.e. keep the backup files).
mergetool.<tool>.path::
Override the path for the given tool. This is useful in case
your tool is not in the PATH.
mergetool.<tool>.cmd::
Specify the command to invoke the specified merge tool.
+
See the `--tool=<tool>` option above for more details.
SEE ALSO
--------
linkgit:git-diff[7]::
Show changes between commits, commit and working tree, etc
linkgit:git-mergetool[1]::
Run merge conflict resolution tools to resolve merge conflicts
linkgit:git-config[7]::
Get and set repository or global options
AUTHOR
------
Written by David Aguilar <davvid@gmail.com>.
Documentation
--------------
Documentation by David Aguilar and the git-list <git@vger.kernel.org>.
GIT
---
Part of the linkgit:git[1] suite