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