git-difftool--helper.sh

   1 #!/bin/sh
   2 # git-difftool--helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
   3 # This script is typically launched by using the 'git difftool'
   4 # convenience command.
   5 #
   6 # Copyright (c) 2009 David Aguilar
   7
   8 # difftool.prompt controls the default prompt/no-prompt behavior
   9 # and is overridden with $GIT_DIFFTOOL*_PROMPT.
  10 should_prompt () {
  11         prompt=$(git config --bool difftool.prompt || echo true)
  12         if test "$prompt" = true; then
  13                 test -z "$GIT_DIFFTOOL_NO_PROMPT"
  14         else
  15                 test -n "$GIT_DIFFTOOL_PROMPT"
  16         fi
  17 }
  18
  19 # This function prepares temporary files and launches the appropriate
  20 # merge tool.
  21 launch_merge_tool () {
  22         # Merged is the filename as it appears in the work tree
  23         # Local is the contents of a/filename
  24         # Remote is the contents of b/filename
  25         # Custom merge tool commands might use $BASE so we provide it
  26         MERGED="$1"
  27         LOCAL="$2"
  28         REMOTE="$3"
  29         BASE="$1"
  30
  31         # $LOCAL and $REMOTE are temporary files so prompt
  32         # the user with the real $MERGED name before launching $merge_tool.
  33         if should_prompt; then
  34                 printf "\nViewing: '$MERGED'\n"
  35                 printf "Hit return to launch '%s': " "$merge_tool"
  36                 read ans
  37         fi
  38
  39         # Run the appropriate merge tool command
  40         case "$merge_tool" in
  41         kdiff3)
  42                 basename=$(basename "$MERGED")
  43                 "$merge_tool_path" --auto \
  44                         --L1 "$basename (A)" \
  45                         --L2 "$basename (B)" \
  46                         "$LOCAL" "$REMOTE" \
  47                         > /dev/null 2>&1
  48                 ;;
  49
  50         kompare)
  51                 "$merge_tool_path" "$LOCAL" "$REMOTE"
  52                 ;;
  53
  54         tkdiff)
  55                 "$merge_tool_path" "$LOCAL" "$REMOTE"
  56                 ;;
  57
  58         meld)
  59                 "$merge_tool_path" "$LOCAL" "$REMOTE"
  60                 ;;
  61
  62         diffuse)
  63                 "$merge_tool_path" "$LOCAL" "$REMOTE" | cat
  64                 ;;
  65
  66         vimdiff)
  67                 "$merge_tool_path" -d -c "wincmd l" "$LOCAL" "$REMOTE"
  68                 ;;
  69
  70         gvimdiff)
  71                 "$merge_tool_path" -d -c "wincmd l" -f "$LOCAL" "$REMOTE"
  72                 ;;
  73
  74         xxdiff)
  75                 "$merge_tool_path" \
  76                         -R 'Accel.Search: "Ctrl+F"' \
  77                         -R 'Accel.SearchForward: "Ctrl-G"' \
  78                         "$LOCAL" "$REMOTE"
  79                 ;;
  80
  81         opendiff)
  82                 "$merge_tool_path" "$LOCAL" "$REMOTE" | cat
  83                 ;;
  84
  85         ecmerge)
  86                 "$merge_tool_path" "$LOCAL" "$REMOTE" \
  87                         --default --mode=merge2 --to="$MERGED"
  88                 ;;
  89
  90         emerge)
  91                 "$merge_tool_path" -f emerge-files-command \
  92                         "$LOCAL" "$REMOTE" "$(basename "$MERGED")"
  93                 ;;
  94
  95         *)
  96                 if test -n "$merge_tool_cmd"; then
  97                         ( eval $merge_tool_cmd )
  98                 fi
  99                 ;;
 100         esac
 101 }
 102
 103 # Verifies that (difftool|mergetool).<tool>.cmd exists
 104 valid_custom_tool() {
 105         merge_tool_cmd="$(git config difftool.$1.cmd)"
 106         test -z "$merge_tool_cmd" &&
 107         merge_tool_cmd="$(git config mergetool.$1.cmd)"
 108         test -n "$merge_tool_cmd"
 109 }
 110
 111 # Verifies that the chosen merge tool is properly setup.
 112 # Built-in merge tools are always valid.
 113 valid_tool() {
 114         case "$1" in
 115         kdiff3 | kompare | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
 116                 ;; # happy
 117         *)
 118                 if ! valid_custom_tool "$1"
 119                 then
 120                         return 1
 121                 fi
 122                 ;;
 123         esac
 124 }
 125
 126 # Sets up the merge_tool_path variable.
 127 # This handles the difftool.<tool>.path configuration.
 128 # This also falls back to mergetool defaults.
 129 init_merge_tool_path() {
 130         merge_tool_path=$(git config difftool."$1".path)
 131         test -z "$merge_tool_path" &&
 132         merge_tool_path=$(git config mergetool."$1".path)
 133         if test -z "$merge_tool_path"; then
 134                 case "$1" in
 135                 vimdiff)
 136                         merge_tool_path=vim
 137                         ;;
 138                 gvimdiff)
 139                         merge_tool_path=gvim
 140                         ;;
 141                 emerge)
 142                         merge_tool_path=emacs
 143                         ;;
 144                 *)
 145                         merge_tool_path="$1"
 146                         ;;
 147                 esac
 148         fi
 149 }
 150
 151 # Allow GIT_DIFF_TOOL and GIT_MERGE_TOOL to provide default values
 152 test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
 153 test -n "$GIT_DIFF_TOOL" && merge_tool="$GIT_DIFF_TOOL"
 154
 155 # If merge tool was not specified then use the diff.tool
 156 # configuration variable.  If that's invalid then reset merge_tool.
 157 # Fallback to merge.tool.
 158 if test -z "$merge_tool"; then
 159         merge_tool=$(git config diff.tool)
 160         test -z "$merge_tool" &&
 161         merge_tool=$(git config merge.tool)
 162         if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
 163                 echo >&2 "git config option diff.tool set to unknown tool: $merge_tool"
 164                 echo >&2 "Resetting to default..."
 165                 unset merge_tool
 166         fi
 167 fi
 168
 169 # Try to guess an appropriate merge tool if no tool has been set.
 170 if test -z "$merge_tool"; then
 171         # We have a $DISPLAY so try some common UNIX merge tools
 172         if test -n "$DISPLAY"; then
 173                 # If gnome then prefer meld, otherwise, prefer kdiff3 or kompare
 174                 if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
 175                         merge_tool_candidates="meld kdiff3 kompare tkdiff xxdiff gvimdiff diffuse"
 176                 else
 177                         merge_tool_candidates="kdiff3 kompare tkdiff xxdiff meld gvimdiff diffuse"
 178                 fi
 179         fi
 180         if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
 181                 # $EDITOR is emacs so add emerge as a candidate
 182                 merge_tool_candidates="$merge_tool_candidates emerge opendiff vimdiff"
 183         elif echo "${VISUAL:-$EDITOR}" | grep 'vim' > /dev/null 2>&1; then
 184                 # $EDITOR is vim so add vimdiff as a candidate
 185                 merge_tool_candidates="$merge_tool_candidates vimdiff opendiff emerge"
 186         else
 187                 merge_tool_candidates="$merge_tool_candidates opendiff emerge vimdiff"
 188         fi
 189         echo "merge tool candidates: $merge_tool_candidates"
 190
 191         # Loop over each candidate and stop when a valid merge tool is found.
 192         for i in $merge_tool_candidates
 193         do
 194                 init_merge_tool_path $i
 195                 if type "$merge_tool_path" > /dev/null 2>&1; then
 196                         merge_tool=$i
 197                         break
 198                 fi
 199         done
 200
 201         if test -z "$merge_tool" ; then
 202                 echo "No known merge resolution program available."
 203                 exit 1
 204         fi
 205
 206 else
 207         # A merge tool has been set, so verify that it's valid.
 208         if ! valid_tool "$merge_tool"; then
 209                 echo >&2 "Unknown merge tool $merge_tool"
 210                 exit 1
 211         fi
 212
 213         init_merge_tool_path "$merge_tool"
 214
 215         if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
 216                 echo "The merge tool $merge_tool is not available as '$merge_tool_path'"
 217                 exit 1
 218         fi
 219 fi
 220
 221
 222 # Launch the merge tool on each path provided by 'git diff'
 223 while test $# -gt 6
 224 do
 225         launch_merge_tool "$1" "$2" "$5"
 226         shift 7
 227 done