First off, I feel the need to be a little defensive and say "This ain't *my* code!" It was in a module written by the head developer of my current client.

Ok, with that out of the way....

Your suggestion about picking from a list of acceptable files is a good one, but wouldn't work in this case (because of information that was not given in the original post). This code was used in a CGI environment and $dest was derived from a CGI param, but this wasn't code that was directly user-interactive, it was called from a PHP script.

As to testing files with -e, -f, and -d before opening them...remember that doing this: 

    line 1)  if ( -e $file && -f $file && -s $file < $ok ) {
    line 2)     ...open file here....
             }

[download]
means that you have a race condition. If someone modifies or deletes $file in the moment between lines 1 and 2, the tests were all for nothing. A better solution is to do something like this (almost directly lifted from perlopentut): 

    use 5.004;
    use Fcntl qw(:DEFAULT :flock);
    open(FH, '<', $file)  or die "can't open $file: $!";
    unless (flock(FH, LOCK_SH | LOCK_NB)) {
    local $| = 1;
    print "Waiting for lock...";
    flock(FH, LOCK_SH)  or die "can't lock $file: $!";
    print "got it.\n"
    } 
    # now read from FH

[download]

In reply to Re^2: Bad code from the trenches by Whitehawke
in thread Bad code from the trenches by Whitehawke

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