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