Rm (Unix) - User-proofing

User-proofing

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Systems administrators, designers, and even users often attempt to defend themselves against accidentally deleting files by creating an alias or function along the lines of:

alias rm="rm -i" rm { /bin/rm -i "$@" ; }

This results in rm asking the user to confirm on a file-by-file basis whether it should be deleted, by pressing the Y or N key. Unfortunately, this tends to train users to be careless about the wildcards they hand into their rm commands, as well as encouraging a tendency to alternately pound y and the return key to affirm removes - until just past the one file they needed to keep. Users have even been seen going as far as "yes | rm files".

A compromise that allows users to confirm just once, encourages proper wildcarding, and makes verification of the list easier can be achieved with something like:

if ; then rm { ls -FCsd "$@" echo 'remove? ' | tr -d '\012' ; read if ; then /bin/rm -rf "$@" else echo '(cancelled)' fi } fi

It's important to note that this function should not be made into a shell script, which would run a risk of it being found ahead of the system rm in the search path, nor should it be allowed in non-interactive shells where it could break batch jobs. Enclosing the definition in the if ; then .... ; fi construct protects against the latter.

There exist third-party wrappers that prevent accidental deletion of important files, like "safe-rm".