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