Friday, April 24, 2009

Preg_Match PHP Function

Preg_Match PHP function is used to search a string, and return a 1 or 0. If the search was successful a 1 will be returned, and if it was not found a 0 will be returned. Although other variables can be added, it is most simply phrased as: preg_match(search_pattern, your_string).

There are two scripts which validates the format of a url text string and domain. It might be used to check the url submitted from a form. The format of the url is expected to be of the form: for example.

  • First script validates a url. This make use of regular expression pattern matching.

//url validation

$url = '';

if (preg_match ("/^[a-z0-9][a-z0-9\-]+[a-z0-9](\.[a-z]{2,4})+$/i", $url)) {

print "$url url OK.";

} else {

print "$url url not valid!";


  • Second script validates a domain.

//domain validation

$domain = 'teSTgjhgj';

if (preg_match ("/^[a-z0-9][a-z0-9\-]+[a-z0-9]$/i", $domain)) {

print "$domain Domain OK.";

} else {

print "$domain Domain not valid!";



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