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

Here is a pre-commit hook with @miku's detailed error message for Linux:

#!/bin/sh

REPOS="$1"
TXN="$2"

SVNLOOK=/usr/bin/svnlook
$SVNLOOK log -t "$TXN" "$REPOS" | \
   grep "[a-zA-Z0-9]" > /dev/null

GREP_STATUS=$?
if [ $GREP_STATUS -ne 0 ]
then
    echo "Your commit has been blocked because you didn't give any log message" 1>&2
    echo "Please write a log message describing the purpose of your changes and" 1>&2
    echo "then try committing again. -- Thank you" 1>&2
    exit 1
fi
exit 0