The subroutine glob2pat from the Perl Cookbook is well known and often quoted (including a couple of nodes here), but I've just used it for the first time. I find it hard to belive that I'm the first person to find a bug in it. SuperSearch on glob2pat didn't show the bug, and neither did Google.
 [0-9] gets converted to ^[0\-9]$.
In other words it does not convert a range correctly since the hyphen is escaped. It is the \Q wot does it. My solution is simple:
sub glob2pat {
    my $globstr = shift;
    my %patmap = (
        '*' => '.*',
        '?' => '.',
        '[' => '[',
        ']' => ']',
        '-' => '-',   # Added by me
    );
    
    $globstr =~ s{(.)} { $patmap{$1} || "\Q$1" }ge;
    
    return '^' . $globstr . '$';
}

[download]
Or am I wrong? This really puzzles me, because it has been around for so long.

Update: I have since realised that neither the original code or my "solution" copes with any escaped characters, like \?, \[, or \*. To make matters worse these characters inside [] should not be converted at all, but they get converted regardless.
Update 2: The following solves the escaped characters, but still does not solve ? and * inside [] which should not be translated:
$globstr =~ s{(?:^|(?<=[^\\]))(.)} { $patmap{$1} || "\Q$1" }ge;

[download]

In reply to Bug in glob2pat? by cdarke

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