Articles

Blocking rm -rf in Claude Code: A Deny Rule Stopped 14 Deletes in Two Weeks, 7 Other Spellings Still Get Through, and a Hook That Closes the Gap

To keep Claude Code from deleting things by accident, I added a deny rule, Bash(rm -rf *), to my global settings. Across my sessions from October 7 to 21 it blocked 14 deletes. After each denial the model picked a new directory name 8 times and dropped the delete 6 times. It never tried another spelling. Then I replayed 22 delete commands verbatim against Claude Code 2.1.285 through a stub. rm -fr, rm -r -f, rm -Rf and rm -r deleted the directory in manual, auto and bypass mode alike. /bin/rm, find -delete and bash -c deleted it in manual and bypass mode. In auto mode, rm -fr inside the working directory skips the classifier because it 'would be allowed in acceptEdits mode'. A second, built-in dangerous-rm check fires on targets like $D/*, even in bypass mode, but loses track of a variable assignment when a heredoc comes earlier in the same command. The post ends with a PreToolUse hook that blocks every recursive spelling in all three modes and tells the model what to do instead.