contrib: add 'git difftool' for launching common merge tools
[git/git.git] / contrib / difftool / git-difftool-helper
CommitLineData
5c38ea31
DA
1#!/bin/sh
2# git-difftool-helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
3# It supports kdiff3, tkdiff, xxdiff, meld, opendiff, emerge, ecmerge,
4# vimdiff, gvimdiff, and custom user-configurable tools.
5# This script is typically launched by using the 'git difftool'
6# convenience command.
7#
8# Copyright (c) 2009 David Aguilar
9
10# Set GIT_DIFFTOOL_NO_PROMPT to bypass the per-file prompt.
11should_prompt () {
12 ! test -n "$GIT_DIFFTOOL_NO_PROMPT"
13}
14
15# Should we keep the backup .orig file?
16keep_backup_mode="$(git config --bool merge.keepBackup || echo true)"
17keep_backup () {
18 test "$keep_backup_mode" = "true"
19}
20
21# This function manages the backup .orig file.
22# A backup $MERGED.orig file is created if changes are detected.
23cleanup_temp_files () {
24 if test -n "$MERGED"; then
25 if keep_backup && test "$MERGED" -nt "$BACKUP"; then
26 test -f "$BACKUP" && mv -- "$BACKUP" "$MERGED.orig"
27 else
28 rm -f -- "$BACKUP"
29 fi
30 fi
31}
32
33# This is called when users Ctrl-C out of git-difftool-helper
34sigint_handler () {
35 echo
36 cleanup_temp_files
37 exit 1
38}
39
40# This function prepares temporary files and launches the appropriate
41# merge tool.
42launch_merge_tool () {
43 # Merged is the filename as it appears in the work tree
44 # Local is the contents of a/filename
45 # Remote is the contents of b/filename
46 # Custom merge tool commands might use $BASE so we provide it
47 MERGED="$1"
48 LOCAL="$2"
49 REMOTE="$3"
50 BASE="$1"
51 ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
52 BACKUP="$MERGED.BACKUP.$ext"
53
54 # Create and ensure that we clean up $BACKUP
55 test -f "$MERGED" && cp -- "$MERGED" "$BACKUP"
56 trap sigint_handler SIGINT
57
58 # $LOCAL and $REMOTE are temporary files so prompt
59 # the user with the real $MERGED name before launching $merge_tool.
60 if should_prompt; then
61 printf "\nViewing: '$MERGED'\n"
62 printf "Hit return to launch '%s': " "$merge_tool"
63 read ans
64 fi
65
66 # Run the appropriate merge tool command
67 case "$merge_tool" in
68 kdiff3)
69 basename=$(basename "$MERGED")
70 "$merge_tool_path" --auto \
71 --L1 "$basename (A)" \
72 --L2 "$basename (B)" \
73 -o "$MERGED" "$LOCAL" "$REMOTE" \
74 > /dev/null 2>&1
75 ;;
76
77 tkdiff)
78 "$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
79 ;;
80
81 meld|vimdiff)
82 "$merge_tool_path" "$LOCAL" "$REMOTE"
83 ;;
84
85 gvimdiff)
86 "$merge_tool_path" -f "$LOCAL" "$REMOTE"
87 ;;
88
89 xxdiff)
90 "$merge_tool_path" \
91 -X \
92 -R 'Accel.SaveAsMerged: "Ctrl-S"' \
93 -R 'Accel.Search: "Ctrl+F"' \
94 -R 'Accel.SearchForward: "Ctrl-G"' \
95 --merged-file "$MERGED" \
96 "$LOCAL" "$REMOTE"
97 ;;
98
99 opendiff)
100 "$merge_tool_path" "$LOCAL" "$REMOTE" \
101 -merge "$MERGED" | cat
102 ;;
103
104 ecmerge)
105 "$merge_tool_path" "$LOCAL" "$REMOTE" \
106 --default --mode=merge2 --to="$MERGED"
107 ;;
108
109 emerge)
110 "$merge_tool_path" -f emerge-files-command \
111 "$LOCAL" "$REMOTE" "$(basename "$MERGED")"
112 ;;
113
114 *)
115 if test -n "$merge_tool_cmd"; then
116 ( eval $merge_tool_cmd )
117 fi
118 ;;
119 esac
120
121 cleanup_temp_files
122}
123
124# Verifies that mergetool.<tool>.cmd exists
125valid_custom_tool() {
126 merge_tool_cmd="$(git config mergetool.$1.cmd)"
127 test -n "$merge_tool_cmd"
128}
129
130# Verifies that the chosen merge tool is properly setup.
131# Built-in merge tools are always valid.
132valid_tool() {
133 case "$1" in
134 kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
135 ;; # happy
136 *)
137 if ! valid_custom_tool "$1"
138 then
139 return 1
140 fi
141 ;;
142 esac
143}
144
145# Sets up the merge_tool_path variable.
146# This handles the mergetool.<tool>.path configuration.
147init_merge_tool_path() {
148 merge_tool_path=$(git config mergetool."$1".path)
149 if test -z "$merge_tool_path"; then
150 case "$1" in
151 emerge)
152 merge_tool_path=emacs
153 ;;
154 *)
155 merge_tool_path="$1"
156 ;;
157 esac
158 fi
159}
160
161# Allow the GIT_MERGE_TOOL variable to provide a default value
162test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
163
164# If not merge tool was specified then use the merge.tool
165# configuration variable. If that's invalid then reset merge_tool.
166if test -z "$merge_tool"; then
167 merge_tool=$(git config merge.tool)
168 if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
169 echo >&2 "git config option merge.tool set to unknown tool: $merge_tool"
170 echo >&2 "Resetting to default..."
171 unset merge_tool
172 fi
173fi
174
175# Try to guess an appropriate merge tool if no tool has been set.
176if test -z "$merge_tool"; then
177
178 # We have a $DISPLAY so try some common UNIX merge tools
179 if test -n "$DISPLAY"; then
180 merge_tool_candidates="kdiff3 tkdiff xxdiff meld gvimdiff"
181 # If gnome then prefer meld
182 if test -n "$GNOME_DESKTOP_SESSION_ID"; then
183 merge_tool_candidates="meld $merge_tool_candidates"
184 fi
185 # If KDE then prefer kdiff3
186 if test "$KDE_FULL_SESSION" = "true"; then
187 merge_tool_candidates="kdiff3 $merge_tool_candidates"
188 fi
189 fi
190
191 # $EDITOR is emacs so add emerge as a candidate
192 if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
193 merge_tool_candidates="$merge_tool_candidates emerge"
194 fi
195
196 # $EDITOR is vim so add vimdiff as a candidate
197 if echo "${VISUAL:-$EDITOR}" | grep 'vim' > /dev/null 2>&1; then
198 merge_tool_candidates="$merge_tool_candidates vimdiff"
199 fi
200
201 merge_tool_candidates="$merge_tool_candidates opendiff emerge vimdiff"
202 echo "merge tool candidates: $merge_tool_candidates"
203
204 # Loop over each candidate and stop when a valid merge tool is found.
205 for i in $merge_tool_candidates
206 do
207 init_merge_tool_path $i
208 if type "$merge_tool_path" > /dev/null 2>&1; then
209 merge_tool=$i
210 break
211 fi
212 done
213
214 if test -z "$merge_tool" ; then
215 echo "No known merge resolution program available."
216 exit 1
217 fi
218
219else
220 # A merge tool has been set, so verify that it's valid.
221 if ! valid_tool "$merge_tool"; then
222 echo >&2 "Unknown merge tool $merge_tool"
223 exit 1
224 fi
225
226 init_merge_tool_path "$merge_tool"
227
228 if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
229 echo "The merge tool $merge_tool is not available as '$merge_tool_path'"
230 exit 1
231 fi
232fi
233
234
235# Launch the merge tool on each path provided by 'git diff'
236while test $# -gt 6
237do
238 launch_merge_tool "$1" "$2" "$5"
239 shift 7
240done