Re: Inverse regexes for input validation

/^[^A-Za-z\-\ ]+$/ will only match if the string contains only bad characters.

sub validate_text
{
        my ($text) = @_;

        if ($text =~ s/[^A-Za-z0-9 -]+//g) {
                print "Funny business fixed\n";
        } else {
                print "Text was already clean\n";
        }

        return $text;
}

my $validated = validate_text($test1);
[download]

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Re^2: Inverse regexes for input validation by chris-lon (Initiate) on Mar 28, 2007 at 17:00 UTC
thanks for that, seems I overcomplicated it far too much and wasn't using local vars properly turns out all I needed was `my ($text) = @_; $text =~ s/[^A-Za-z0-9 -]+//g; return $text;` [download] thanks very much for the help.	[reply] [d/l]
Re^3: Inverse regexes for input validation by graff (Chancellor) on Mar 29, 2007 at 01:15 UTC
Not that it makes a whole lot of difference in your case, but the "tr///" operator is especially good for this sort of thing -- it's demonstrably faster than "s///" (utf8 wide characters don't even seem to slow it down), and the syntax is a little easier: `my ( $text ) = shift; $text =~ tr/ 0-9A-Za-z-//cd; return $text;` [download] The "c" modifier says the match should apply to the complement of the characters cited, and with no characters in the replacement side, "d" says delete all matched characters.	[reply] [d/l]