You're probably best off doing something like this: 
($untainted) = $file =~ /^(.*)$/s;

[download]
Just be certain you only use $untainted in a "secure" way. I suspect a rename call is fine, but don't think of using it in, say, system.

The example you used ($filename=~/^(.+)$/; $file=$1;) breaks if there's a newline in the filename and if it doesn't successfully match the filename, you could be setting $file to something you do not expect (since an unsuccessful match leaves $1 to what it was set to before). Taint-checking probably wouldn't pick up on this mistake.

In reply to Re: Untainting 'bad' filenames by Fastolfe
in thread Untainting 'bad' filenames by doran

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