note 48277 deleted from function.preg-match by colder
| From: | colder@php.net | Date: | Mon, 18 Jun 2007 18:19:24 +0000 |
| Subject: | note 48277 deleted from function.preg-match by colder | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-127591@lists.php.net to get a copy of this message | ||
Note Submitter: satch666 at dot nospam dot hotmail dot com
----
some fix for the function valid_ipv4() proposed by selt:
if trying, for example this wrong IP: 257.255.34.6, it is got as valid IP, getting as result:
57.255.34.6
the first subpattern of numbers defined at pattern matches with '257', because
'57' is a valid string for '1?\d\d' pattern; this happens because it is not
added there some logic for the string limits ...;
i have tried using '^1?\d\d$', and it works, as we are saying in plain english: if the
string has 3 chars, then it is starting by '1' digit and followed by other 2, ending the
string there; if it has 2 chars, then both are any digit; any other case out of this 2 doesnt match
the pattern; in other words, it is defined the subrange of numbers from '10' to
'199'
so the function would get as this (after modifying pattern and erasing a var, called $range, not
used at function):
<?
function valid_ipv4($ip_addr)
{
$num="([0-9]|^1?\d\d$|2[0-4]\d|25[0-5])";
if(preg_match("/$num\.$num\.$num\.$num/",$ip_addr,$matches))
{
return $matches[0];
} else {
return false;
}
}
?>