pre-push hook to check gitversion.h against tag

As discussed in #35

scripts/pre-push.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+## hook to check version match tag before push
+## usage: ln -s ../../scripts/pre-push.sh .git/hooks/pre-push
+
+VERSIONFILE="gitversion.h"
+BRANCH="HEAD"
+
+tagref=$(grep -Po 'refs/tags/([^ ]*) ' </dev/stdin | head -n1 | cut -c11- | tr -d '[:space:]')
+
+if [[ "$tagref" == ""  ]]; then
+    ## pushing without --tags , exit normally
+    exit 0
+fi
+
+## versionline may looks like '#define GITVERSION "0.0.8"'
+versionline=$(git cat-file blob $BRANCH:"$VERSIONFILE" | grep 'GITVERSION')
+ver=$(echo "$versionline" | sed 's/^[^"]*"//;s/"[^"]*$//')
+
+if [[ "$tagref" == "$ver" ]]; then
+    ## tag matches ver
+    exit 0
+fi
+echo "Tag name don't match version file. Preventing push."
+echo "tag name: $tagref"
+echo "version: $ver"
+exit 1