Hi,

I have some code that accepts a string from a user to use as a regular expression in a filter. (E.g if they want the script to output a list of items beginning abc they would enter ^abc .)

This bit works well when they enter a valid regular expression. However I'm struggling with a way of validating the regexp prior to using it (ie make sure they've entered a valid regexp, not worried at this stage what it matches just that it's a valid string). The best I've come up with it

use strict;
use warnings;

print validate('a*') . "\n";
print validate('*') . "\n";

sub validate{
    my $pat = shift;
    if (eval{qr/$pat/}){
        return 1;
    }else{
        return 0;
    }
}

[download]

This works but feels like a rather ugly way to do this. Can anyone think of a better way?

I can't just use \Q and \E, I want them to be able to enter meta characters.

Thanks

Graham

In reply to Validating Regular Expression by Anonymous Monk

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