How can I prevent Subversion commits without comments?

Question

Does anybody know how to prevent commits to a Subversion code repository when there is no commit comment entered?

Answer 1

Actually, when you create a Subversion repository, its hooks subdirectory already contains hook samples. Check out the one called pre-commit.tmpl for details on the hook's parameters. It also contains an example for a hook that you're looking for:

#!/bin/sh
REPOS="$1"
TXN="$2"

# Make sure that the log message contains some text.
SVNLOOK=/usr/local/bin/svnlook
$SVNLOOK log -t "$TXN" "$REPOS" | \
   grep "[a-zA-Z0-9]" > /dev/null || exit 1

You can write your hook in any script or language, as long as it's executable on your Subversion machine.