SVN pre-commit hook for avoiding changes to tags subdirectories

Question

Is there anybody who has clear instructions on how to add a pre-commit hook that avoids changes to tags subdirectories?

I already searched the internet quite a bit.

Answer 1

The accepted answer prevents updating files in a tag but doesn't prevent adding files to a tag. The following version handles both:

#!/bin/sh

REPOS="$1"
TXN="$2"
SVNLOOK="/home/staging/thirdparty/subversion-1.6.17/bin/svnlook"

# Committing to tags is not allowed
$SVNLOOK changed -t "$TXN" "$REPOS" --copy-info| grep -v "^ " | grep -P '^[AU]   \w+/tags/' && /bin/echo "Cannot update tags!" 1>&2 && exit 1

# All checks passed, so allow the commit.
exit 0