diff --git a/.githooks/post-merge b/.githooks/post-merge
index 8ff70b3..52b4ebb 100755
--- a/.githooks/post-merge
+++ b/.githooks/post-merge
@@ -17,6 +17,27 @@ OPKG_CMDS_TMP=/tmp/opkg_commands
 rm -f $GIT_PULL_TMP
 rm -f $OPKG_CMDS_TMP
 
+get_blob () {   # get the blob of the file(name) passed as $1
+                # note: this can be used for any file in the filesystem
+    echo $(git hash-object $1)
+}
+
+get_commit_for_blob () {
+    blob=$(get_blob $1)
+    if [ ! -z $blob ]; then
+        # search for the blob in all commits for the file(name) $1
+        echo $(echo $(git log --all --pretty=format:%H -- $1) |
+               xargs -I{} bash -c "git ls-tree {} -- $1       |
+               grep -q $blob && echo {}")
+    fi
+}
+
+changed_file_names () {
+    for fn in $(git diff-tree -r HEAD@{1} HEAD --name-only); do
+        CHANGED_FILE_NAMES+=($fn)
+    done
+}
+
 for fn in $(git diff-tree -r HEAD@{1} HEAD --name-only); do
     if grep -E -q "(DC.*json|dc.*hex|dc.*bin|tariff.*json)" <<< $fn; then
         fsize=0