contrib/difftool: use a separate config namespace for difftool commands
[git/git.git] / contrib / difftool / git-difftool-helper
1 #!/bin/sh
2 # git-difftool-helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
3 # It supports kdiff3, kompare, tkdiff, xxdiff, meld, opendiff,
4 # emerge, ecmerge, 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.
11 should_prompt () {
12 ! test -n "$GIT_DIFFTOOL_NO_PROMPT"
13 }
14
15 # Should we keep the backup .orig file?
16 keep_backup_mode="$(git config --bool merge.keepBackup || echo true)"
17 keep_backup () {
18 test "$keep_backup_mode" = "true"
19 }
20
21 # This function manages the backup .orig file.
22 # A backup $MERGED.orig file is created if changes are detected.
23 cleanup_temp_files () {
24 if test -n "$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
34 sigint_handler () {
35 cleanup_temp_files
36 exit 1
37 }
38
39 # This function prepares temporary files and launches the appropriate
40 # merge tool.
41 launch_merge_tool () {
42 # Merged is the filename as it appears in the work tree
43 # Local is the contents of a/filename
44 # Remote is the contents of b/filename
45 # Custom merge tool commands might use $BASE so we provide it
46 MERGED="$1"
47 LOCAL="$2"
48 REMOTE="$3"
49 BASE="$1"
50 ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
51 BACKUP="$MERGED.BACKUP.$ext"
52
53 # Create and ensure that we clean up $BACKUP
54 test -f "$MERGED" && cp -- "$MERGED" "$BACKUP"
55 trap sigint_handler INT
56
57 # $LOCAL and $REMOTE are temporary files so prompt
58 # the user with the real $MERGED name before launching $merge_tool.
59 if should_prompt; then
60 printf "\nViewing: '$MERGED'\n"
61 printf "Hit return to launch '%s': " "$merge_tool"
62 read ans
63 fi
64
65 # Run the appropriate merge tool command
66 case "$merge_tool" in
67 kdiff3)
68 basename=$(basename "$MERGED")
69 "$merge_tool_path" --auto \
70 --L1 "$basename (A)" \
71 --L2 "$basename (B)" \
72 -o "$MERGED" "$LOCAL" "$REMOTE" \
73 > /dev/null 2>&1
74 ;;
75
76 kompare)
77 "$merge_tool_path" "$LOCAL" "$REMOTE"
78 ;;
79
80 tkdiff)
81 "$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
82 ;;
83
84 meld)
85 "$merge_tool_path" "$LOCAL" "$REMOTE"
86 ;;
87
88 vimdiff)
89 "$merge_tool_path" -c "wincmd l" "$LOCAL" "$REMOTE"
90 ;;
91
92 gvimdiff)
93 "$merge_tool_path" -c "wincmd l" -f "$LOCAL" "$REMOTE"
94 ;;
95
96 xxdiff)
97 "$merge_tool_path" \
98 -X \
99 -R 'Accel.SaveAsMerged: "Ctrl-S"' \
100 -R 'Accel.Search: "Ctrl+F"' \
101 -R 'Accel.SearchForward: "Ctrl-G"' \
102 --merged-file "$MERGED" \
103 "$LOCAL" "$REMOTE"
104 ;;
105
106 opendiff)
107 "$merge_tool_path" "$LOCAL" "$REMOTE" \
108 -merge "$MERGED" | cat
109 ;;
110
111 ecmerge)
112 "$merge_tool_path" "$LOCAL" "$REMOTE" \
113 --default --mode=merge2 --to="$MERGED"
114 ;;
115
116 emerge)
117 "$merge_tool_path" -f emerge-files-command \
118 "$LOCAL" "$REMOTE" "$(basename "$MERGED")"
119 ;;
120
121 *)
122 if test -n "$merge_tool_cmd"; then
123 ( eval $merge_tool_cmd )
124 fi
125 ;;
126 esac
127
128 cleanup_temp_files
129 }
130
131 # Verifies that (difftool|mergetool).<tool>.cmd exists
132 valid_custom_tool() {
133 merge_tool_cmd="$(git config difftool.$1.cmd)"
134 test -z "$merge_tool_cmd" &&
135 merge_tool_cmd="$(git config mergetool.$1.cmd)"
136 test -n "$merge_tool_cmd"
137 }
138
139 # Verifies that the chosen merge tool is properly setup.
140 # Built-in merge tools are always valid.
141 valid_tool() {
142 case "$1" in
143 kdiff3 | kompare | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
144 ;; # happy
145 *)
146 if ! valid_custom_tool "$1"
147 then
148 return 1
149 fi
150 ;;
151 esac
152 }
153
154 # Sets up the merge_tool_path variable.
155 # This handles the difftool.<tool>.path configuration.
156 # This also falls back to mergetool defaults.
157 init_merge_tool_path() {
158 merge_tool_path=$(git config difftool."$1".path)
159 test -z "$merge_tool_path" &&
160 merge_tool_path=$(git config mergetool."$1".path)
161 if test -z "$merge_tool_path"; then
162 case "$1" in
163 emerge)
164 merge_tool_path=emacs
165 ;;
166 *)
167 merge_tool_path="$1"
168 ;;
169 esac
170 fi
171 }
172
173 # Allow GIT_DIFF_TOOL and GIT_MERGE_TOOL to provide default values
174 test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
175 test -n "$GIT_DIFF_TOOL" && merge_tool="$GIT_DIFF_TOOL"
176
177 # If merge tool was not specified then use the diff.tool
178 # configuration variable. If that's invalid then reset merge_tool.
179 # Fallback to merge.tool.
180 if test -z "$merge_tool"; then
181 merge_tool=$(git config diff.tool)
182 test -z "$merge_tool" &&
183 merge_tool=$(git config merge.tool)
184 if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
185 echo >&2 "git config option diff.tool set to unknown tool: $merge_tool"
186 echo >&2 "Resetting to default..."
187 unset merge_tool
188 fi
189 fi
190
191 # Try to guess an appropriate merge tool if no tool has been set.
192 if test -z "$merge_tool"; then
193 # We have a $DISPLAY so try some common UNIX merge tools
194 if test -n "$DISPLAY"; then
195 # If gnome then prefer meld, otherwise, prefer kdiff3 or kompare
196 if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
197 merge_tool_candidates="meld kdiff3 kompare tkdiff xxdiff gvimdiff"
198 else
199 merge_tool_candidates="kdiff3 kompare tkdiff xxdiff meld gvimdiff"
200 fi
201 fi
202 if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
203 # $EDITOR is emacs so add emerge as a candidate
204 merge_tool_candidates="$merge_tool_candidates emerge opendiff vimdiff"
205 elif echo "${VISUAL:-$EDITOR}" | grep 'vim' > /dev/null 2>&1; then
206 # $EDITOR is vim so add vimdiff as a candidate
207 merge_tool_candidates="$merge_tool_candidates vimdiff opendiff emerge"
208 else
209 merge_tool_candidates="$merge_tool_candidates opendiff emerge vimdiff"
210 fi
211 echo "merge tool candidates: $merge_tool_candidates"
212
213 # Loop over each candidate and stop when a valid merge tool is found.
214 for i in $merge_tool_candidates
215 do
216 init_merge_tool_path $i
217 if type "$merge_tool_path" > /dev/null 2>&1; then
218 merge_tool=$i
219 break
220 fi
221 done
222
223 if test -z "$merge_tool" ; then
224 echo "No known merge resolution program available."
225 exit 1
226 fi
227
228 else
229 # A merge tool has been set, so verify that it's valid.
230 if ! valid_tool "$merge_tool"; then
231 echo >&2 "Unknown merge tool $merge_tool"
232 exit 1
233 fi
234
235 init_merge_tool_path "$merge_tool"
236
237 if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
238 echo "The merge tool $merge_tool is not available as '$merge_tool_path'"
239 exit 1
240 fi
241 fi
242
243
244 # Launch the merge tool on each path provided by 'git diff'
245 while test $# -gt 6
246 do
247 launch_merge_tool "$1" "$2" "$5"
248 shift 7
249 done