Regex error: 'Warning: ereg() [function.ereg]: REG_ERANGE' in PHP

Question

The code below gives me this mysterious error, and i cannot fathom it. I am new to regular expressions and so am consequently stumped. The regular expression should be validating any international phone number.

Any help would be much appreciated.

function validate_phone($phone)
{
 $phoneregexp ="^(\+[1-9][0-9]*(\([0-9]*\)|-[0-9]*-))?[0]?[1-9][0-9\- ]*$";

 $phonevalid = 0;

 if (ereg($phoneregexp, $phone))
 {
  $phonevalid = 1;
 }else{
  $phonevalid = 0;
 }
}

Answer 1

If this is PHP, then the regex must be enclosed in quotes. Furthermore, what's preg? Did you mean preg_match?

Another thing. PHP knows boolean values. The canonical solution would rather look like this:

return preg_match($regex, $phone) !== 0;

EDIT: Or, using ereg:

return ereg($regex, $phone) !== FALSE;

(Here, the explicit test against FALSE isn't strictly necessary but since ereg returns a number upon success I feel safer coercing the value into a bool).

Answer 2

Hmm well the code you pasted isn't quite valid, I fixed it up by adding the missing quotes, missing delimiters, and changed preg to preg_match. I didn't get the warning.

Edit: after seeing the other comment, you meant "ereg" not "preg"... that gives the warning. Try using preg_match() instead ;)

<?php
function validate_phone($phone)
{
        $phoneregexp ='/^(\+[1-9][0-9]*(\([0-9]*\)|-[0-9]*-))?[0]?[1-9][0-9\- ]*$/';

        $phonevalid = 0;

        if (preg_match($phoneregexp, $phone))
        {
                $phonevalid = 1;
        }else{
                $phonevalid = 0;
        }
}

validate_phone("123456");
?>

Answer 3

Just to provide some reference material please read

• Regular Expressions (Perl-Compatible)
• preg_match()

or if you'd like to stick with the POSIX regexp:

• Regular Expression (POSIX Extended)
• ereg()

The correct sample code has already been given above.

Answer 4

It's the [0-9\\- ] part of your RE - it's not escaping the "-" properly. Change it to [0-9 -] and you should be OK (a "-" at the last position in a character class is treated as literal, not part of a range specification).