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         echo
  36         cleanup_temp_files
  37         exit 1
  38 }
  39
  40 # This function prepares temporary files and launches the appropriate
  41 # merge tool.
  42 launch_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 $merge_tool_cmd )
 117                 fi
 118                 ;;
 119         esac
 120
 121         cleanup_temp_files
 122 }
 123
 124 # Verifies that mergetool.<tool>.cmd exists
 125 valid_custom_tool() {
 126         merge_tool_cmd="$(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.
 132 valid_tool() {
 133         case "$1" in
 134         kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
 135                 ;; # happy
 136         *)
 137                 if ! valid_custom_tool "$1"
 138                 then
 139                         return 1
 140                 fi
 141                 ;;
 142         esac
 143 }
 144
 145 # Sets up the merge_tool_path variable.
 146 # This handles the mergetool.<tool>.path configuration.
 147 init_merge_tool_path() {
 148         merge_tool_path=$(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="$1"
 156                         ;;
 157                 esac
 158         fi
 159 }
 160
 161 # Allow the GIT_MERGE_TOOL variable to provide a default value
 162 test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
 163
 164 # If not merge tool was specified then use the merge.tool
 165 # configuration variable.  If that's invalid then reset merge_tool.
 166 if test -z "$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: $merge_tool"
 170                 echo >&2 "Resetting to default..."
 171                 unset merge_tool
 172         fi
 173 fi
 174
 175 # Try to guess an appropriate merge tool if no tool has been set.
 176 if test -z "$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
 219 else
 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
 232 fi
 233
 234
 235 # Launch the merge tool on each path provided by 'git diff'
 236 while test $# -gt 6
 237 do
 238         launch_merge_tool "$1" "$2" "$5"
 239         shift 7
 240 done