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