git-identify-revision

   1 #!/bin/sh
   2
   3 # situation: work tree is unknown rev
   4 # arguments: git rev-list arguments
   5 # we now identify the one revision with least differences
   6
   7 case "$1" in
   8         --cached)
   9                 use_worktree=false
  10                 shift
  11                 ;;
  12         *)
  13                 use_worktree=true
  14                 ;;
  15 esac
  16
  17 diffopts="-M -C"
  18
  19 if $use_worktree; then
  20         echo >&2 "Saving index..."
  21         oldindex=`git write-tree`
  22         # set up resetting
  23         trap 'echo >&2 "Restoring index..."; git reset "$oldindex" .' EXIT
  24         trap 'exit 1' INT TERM
  25
  26         echo >&2 "Creating index..."
  27         git add -A
  28 fi
  29
  30 echo >&2 "Listing candidates..."
  31 allrevs=`git rev-list "$@"`
  32
  33 echo >&2 "Evaluating candidates..."
  34 bestrev=
  35 bestrevscore=
  36 for rev in $allrevs; do
  37         score=`git diff $diffopts --cached "$rev" | wc -l`
  38         if [ -z "$bestrevscore" ] || [ "$score" -lt "$bestrevscore" ]; then
  39                 echo >&2 "Improved to $rev (score: $score)"
  40                 bestrev=$rev
  41                 bestrevscore=$score
  42         fi
  43 done
  44 echo >&2 "Done."
  45
  46 echo "$bestrev"
  47 git diff $diffopts --cached "$bestrev" >&2