Merge branch 'jc/maint-format-patch-o-relative'
[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, 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.
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         tkdiff)
77                 "$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
78                 ;;
79
80         meld)
81                 "$merge_tool_path" "$LOCAL" "$REMOTE"
82                 ;;
83
84         vimdiff)
85                 "$merge_tool_path" -c "wincmd l" "$LOCAL" "$REMOTE"
86                 ;;
87
88         gvimdiff)
89                 "$merge_tool_path" -c "wincmd l" -f "$LOCAL" "$REMOTE"
90                 ;;
91
92         xxdiff)
93                 "$merge_tool_path" \
94                         -X \
95                         -R 'Accel.SaveAsMerged: "Ctrl-S"' \
96                         -R 'Accel.Search: "Ctrl+F"' \
97                         -R 'Accel.SearchForward: "Ctrl-G"' \
98                         --merged-file "$MERGED" \
99                         "$LOCAL" "$REMOTE"
100                 ;;
101
102         opendiff)
103                 "$merge_tool_path" "$LOCAL" "$REMOTE" \
104                         -merge "$MERGED" | cat
105                 ;;
106
107         ecmerge)
108                 "$merge_tool_path" "$LOCAL" "$REMOTE" \
109                         --default --mode=merge2 --to="$MERGED"
110                 ;;
111
112         emerge)
113                 "$merge_tool_path" -f emerge-files-command \
114                         "$LOCAL" "$REMOTE" "$(basename "$MERGED")"
115                 ;;
116
117         *)
118                 if test -n "$merge_tool_cmd"; then
119                         ( eval $merge_tool_cmd )
120                 fi
121                 ;;
122         esac
123
124         cleanup_temp_files
125 }
126
127 # Verifies that mergetool.<tool>.cmd exists
128 valid_custom_tool() {
129         merge_tool_cmd="$(git config mergetool.$1.cmd)"
130         test -n "$merge_tool_cmd"
131 }
132
133 # Verifies that the chosen merge tool is properly setup.
134 # Built-in merge tools are always valid.
135 valid_tool() {
136         case "$1" in
137         kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
138                 ;; # happy
139         *)
140                 if ! valid_custom_tool "$1"
141                 then
142                         return 1
143                 fi
144                 ;;
145         esac
146 }
147
148 # Sets up the merge_tool_path variable.
149 # This handles the mergetool.<tool>.path configuration.
150 init_merge_tool_path() {
151         merge_tool_path=$(git config mergetool."$1".path)
152         if test -z "$merge_tool_path"; then
153                 case "$1" in
154                 emerge)
155                         merge_tool_path=emacs
156                         ;;
157                 *)
158                         merge_tool_path="$1"
159                         ;;
160                 esac
161         fi
162 }
163
164 # Allow the GIT_MERGE_TOOL variable to provide a default value
165 test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
166
167 # If not merge tool was specified then use the merge.tool
168 # configuration variable.  If that's invalid then reset merge_tool.
169 if test -z "$merge_tool"; then
170         merge_tool=$(git config merge.tool)
171         if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
172                 echo >&2 "git config option merge.tool set to unknown tool: $merge_tool"
173                 echo >&2 "Resetting to default..."
174                 unset merge_tool
175         fi
176 fi
177
178 # Try to guess an appropriate merge tool if no tool has been set.
179 if test -z "$merge_tool"; then
180
181         # We have a $DISPLAY so try some common UNIX merge tools
182         if test -n "$DISPLAY"; then
183                 merge_tool_candidates="kdiff3 tkdiff xxdiff meld gvimdiff"
184                 # If gnome then prefer meld
185                 if test -n "$GNOME_DESKTOP_SESSION_ID"; then
186                         merge_tool_candidates="meld $merge_tool_candidates"
187                 fi
188                 # If KDE then prefer kdiff3
189                 if test "$KDE_FULL_SESSION" = "true"; then
190                         merge_tool_candidates="kdiff3 $merge_tool_candidates"
191                 fi
192         fi
193
194         # $EDITOR is emacs so add emerge as a candidate
195         if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
196                 merge_tool_candidates="$merge_tool_candidates emerge"
197         fi
198
199         # $EDITOR is vim so add vimdiff as a candidate
200         if echo "${VISUAL:-$EDITOR}" | grep 'vim' > /dev/null 2>&1; then
201                 merge_tool_candidates="$merge_tool_candidates vimdiff"
202         fi
203
204         merge_tool_candidates="$merge_tool_candidates opendiff emerge vimdiff"
205         echo "merge tool candidates: $merge_tool_candidates"
206
207         # Loop over each candidate and stop when a valid merge tool is found.
208         for i in $merge_tool_candidates
209         do
210                 init_merge_tool_path $i
211                 if type "$merge_tool_path" > /dev/null 2>&1; then
212                         merge_tool=$i
213                         break
214                 fi
215         done
216
217         if test -z "$merge_tool" ; then
218                 echo "No known merge resolution program available."
219                 exit 1
220         fi
221
222 else
223         # A merge tool has been set, so verify that it's valid.
224         if ! valid_tool "$merge_tool"; then
225                 echo >&2 "Unknown merge tool $merge_tool"
226                 exit 1
227         fi
228
229         init_merge_tool_path "$merge_tool"
230
231         if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
232                 echo "The merge tool $merge_tool is not available as '$merge_tool_path'"
233                 exit 1
234         fi
235 fi
236
237
238 # Launch the merge tool on each path provided by 'git diff'
239 while test $# -gt 6
240 do
241         launch_merge_tool "$1" "$2" "$5"
242         shift 7
243 done