src/tools/git-external-diff

   1 #!/bin/bash
   2
   3 # This script is used to produce git context diffs
   4
   5 # Supplied parameters:
   6 # $1   $2       $3       $4       $5       $6       $7
   7 # path old-file old-hash old-mode new-file new-hash new-mode
   8 # 'path' is the git-tree-relative path of the file being diff'ed
   9
  10 =comment
  11
  12 This info is copied from the old wiki page on Working with git:
  13
  14 Context diffs with Git
  15
  16 Copy git-external-diff into libexec/git-core/ of your git installation
  17 and configure git to use that wrapper with:
  18
  19     git config [--global] diff.external git-external-diff
  20
  21 --global makes the configuration global for your user - otherwise it is
  22 just configured for the current repository.
  23
  24 For every command which displays diffs in some way you can use the
  25 parameter "--[no-]-ext-diff" to enable respectively disable using the
  26 external diff command.
  27
  28 For the git diff command --ext-diff is enabled by default - for any
  29 other command like git log -p or git format-patch it is not!
  30
  31 This method should work on all platforms supported by git.
  32
  33 If you do not want to configure the external wrapper permanently or you
  34 want to overwrite it you can also invoke git like:
  35
  36     export GIT_EXTERNAL_DIFF=git-external-diff
  37     git diff --[no-]ext-diff
  38
  39 Alternatively, configure a git alias in ~/.gitconfig or .git/config:
  40
  41     [alias]
  42         cdiff = !GIT_EXTERNAL_DIFF=git-context-diff git diff
  43 =cut
  44
  45 old_hash="$3"
  46 new_hash=$(git hash-object "$5")
  47
  48 # no change?
  49 [ "$old_hash" = "$new_hash" ] && exit 0
  50
  51 [ "$DIFF_OPTS" = "" ] && DIFF_OPTS='-pcd'
  52
  53 echo "diff --git a/$1 b/$1"
  54 echo "new file mode $7"
  55 echo "index ${old_hash:0:7}..${new_hash:0:7}"
  56
  57 diff --label a/"$1" --label b/"$1" $DIFF_OPTS "$2" "$5"
  58
  59 exit 0