Warning: preg_match(): Unknown modifier '.' after replacing ereg

Question

I had this original code:

/**
* IP address conversion: A.B.C.D -> log
*
* @param string $string IP Address: A.B.C.D
* @return long
* @access private
* @static
* @since 1.0
*/
private function convert2number($string)
{
    $pattern= "\"([0-9]+)\"";
    if (ereg($pattern, $string, $regs))
        return (int)$regs[1];
}

/**
* IP conversion
*
* @param string $address IP address in the A.B.C.D format
* @return long
* @access private
* @static
* @since 1.0
*/
private function IpAddress2IpNumber($address)
{
    $pattern = "([0-9]+).([0-9]+).([0-9]+).([0-9]+)";

    if (ereg($pattern, $address, $regs))
        return $number = $regs[1] * 256 * 256 * 256 + $regs[2] * 256 * 256 + $regs[3] * 256 + $regs[4];
    else
        return false;
}

Since PHP 5.3, ereg was Deprecated, I researched this, and I stumbled upon a suggestion to replace ereg with preg_match, I did so, and I got a new error:

Warning: preg_match(): Unknown modifier '.' in geoip.php on line 222

Code:

/**
* IP conversion
*
* @param string $address IP address in the A.B.C.D format
* @return long
* @access private
* @static
* @since 1.0
*/
private function IpAddress2IpNumber($address)
{
    $pattern = "([0-9]+).([0-9]+).([0-9]+).([0-9]+)";

    if (preg_match($pattern, $address, $regs))
        return $number = $regs[1] * 256 * 256 * 256 + $regs[2] * 256 * 256 + $regs[3] * 256 + $regs[4];
    else
        return false;
}

How do I go about fixing this? Any recommendation? Thanks!

I removed the CakePHP tag, this has nothing to do with CakePHP. — floriank, Jan 19 '15 at 22:14
RTFM: http://php.net/manual/en/regexp.reference.delimiters.php — CBroe, Jan 19 '15 at 22:15
You're recreating functionality that comes shipped with php http://php.net/manual/en/function.ip2long.php — atxdba, Jan 19 '15 at 22:40

score 1 · Answer 1 · answered Jan 19 '15 at 22:15

1

You need to use delimiters with preg_match. See the docs on this topic.

answered Jan 19 '15 at 22:15

elixenide

44,308
16
74
100

What do I need to edit? I'm new to PHP – Sup3r Jan 19 '15 at 22:15
Your regex has to be preceded and followed by a delimiter. Typical choices are `/`, `\``, and `~`. – elixenide Jan 19 '15 at 22:16
1

@Sup3r Read the docs – Cjmarkham Jan 19 '15 at 22:16
@Sup3r Not sure what you mean. There are no `/`s in `\"([0-9]+)\"`. – elixenide Jan 19 '15 at 22:19
Mind, where do I add it in my regex expression case? – Sup3r Jan 19 '15 at 22:20
1

Delimiters go at the very beginning and end of the expression. – Cjmarkham Jan 19 '15 at 22:21
Like I said, before and after. So, for example, `$pattern = "/([0-9]+).([0-9]+).([0-9]+).([0-9]+)/";` – elixenide Jan 19 '15 at 22:21

harrrrrrry · Accepted Answer · 2015-01-19T22:29:24.600

-1

"." needs a "\" to avoid it be taken as any character.

the pattern needs delimiters for preg_match.

$pattern = "|([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)|";

edited Jan 19 '15 at 22:29

answered Jan 19 '15 at 22:22

harrrrrrry

13,643
2
23
28

Don't just give away code. Explain why there is an issue and describe how to fix it. Like the man and his fishing rod – Cjmarkham Jan 19 '15 at 22:24
Thanks @zairwolf, What's the correct way? `$pattern = "/([0-9]+).([0-9]+).([0-9]+).([0-9]+)/"; ` OR `$pattern = "|([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)|";` – Sup3r Jan 19 '15 at 22:28
A delimiter can be any non-alphanumeric, non-backslash, non-whitespace character.. Read this : http://php.net/manual/en/regexp.reference.delimiters.php – harrrrrrry Jan 19 '15 at 22:30

Warning: preg_match(): Unknown modifier '.' after replacing ereg

2 Answers2