[RESOLVED] preg_match_all help

kingdm

Can anyone help me regarding this preg_match_all I did.

if(preg_match_all('/[^a-z0-9\.,$ñ\s-_]/i', $vesselname, $invalid)) 
				{ 
				   $errors[] = "Vessel name contains invalid character: " . join('',array_unique($invalid[0]));
				}

This works fine however it won't allow the characters / () slash and open&close parentheses. I need those characters to be valid.

Thank you.

Weedpacket

You' put them in between the [ and ] of the regular expression; don't forget about escaping them with \ (incidentally, you don't need to escape the '.').

kingdm

Thanks. Finally learn how to do it.

nrg_alpha

To further add to weedpacket's mentioning of not needing to escape the dot, most meta characters lose their special meaning within the character class (the dot is one of them). Some meta characters might retain their special status, depending on their location within the class - which brings me to this point... note the position of the dash in your pattern (it's nested between the shorthand whitespace character class \s and the underscore.

In essence, you have created a range between whitespace characters and the underscore (much like a-z creates a range between a and z). As a rule, if you wish the dash to be treated as a literal, you should either place it as the very first or last character in the character class, - or - otherwise escape it: - If not, you might get undesireable results depending on the source string in question.

EDIT - Come to think of it, it might not effect ranges of shorthand classes (not entirely sure).. but none the less, in either case, it's a good habit to manage your dashes correctly.

nrg_alpha

Ok, it seems that if a shorthand character class preceeds a dash (when the dash is not the first of last character in the character class), a range is not created (at least, not according to the following test):

$str = 'This is a 123:;<=> test?';
echo $str . "<br />\n";
echo $str = preg_replace('#[\d-?]#', '*', $str); 
// output:
// This is a 123:;<=> test?
// This is a ***:;<=> test*

$str = 'This is a 123:;<=> test?';
echo $str . "<br />\n";
echo $str = preg_replace('#[0-89-?]#', '*', $str);
// output:
// This is a 123:;<=> test?
// This is a ******** test*