t/subtree-hash

   1 #!/usr/bin/env bash
   2
   3 # Usage: subtree-hash ROOT_HASH [SUBDIR ...]
   4
   5 subtree_hash()
   6 {
   7     root_hash="$1"
   8     if test "$#" -eq 1; then
   9         echo $root_hash
  10     else
  11         subdir="$2"
  12         subtree_info="$(git ls-tree "$root_hash" | grep -E "    $subdir\$")" || true
  13         if test "$(echo "$subtree_info" | wc -l)" -ne 1; then
  14             echo "Didn't find just one matching line in subtree $root_hash" 1>&2
  15             return 1
  16         fi
  17
  18         subtree_hash="$(echo "$subtree_info" | cut -d' ' -f 3 | cut -d$'\t' -f 1)" || true
  19         if test -z "$subtree_hash"; then
  20             echo "Unable to find subtree hash in git output: $subtree_info" 1>&2
  21             return 1
  22         fi
  23
  24         shift 2 || exit $?
  25         subtree_hash "$subtree_hash" "$@" || exit $?
  26     fi
  27 }
  28
  29 subtree_hash "$@"