Re: Help: Validate Domain Name by Regular Express

On Sun, 2011-01-09 at 11:37 +0800, WalkinRaven wrote: > On 01/09/2011 01:09 AM, Ashley Sheridan wrote: > > On Sat, 2011-01-08 at 16:55 +0800, WalkinRaven wrote: > > > >> PHP 5.3 PCRE > >> > >> Regular Express to match domain names format according to RFC 1034 - > >> DOMAIN NAMES - CONCEPTS AND FACILITIES > >> > >> /^ > >> ( > >> [a-z] | > >> [a-z] (?:[a-z]|[0-9]) | > >> [a-z] (?:[a-z]|[0-9]|\-){1,61} (?:[a-z]|[0-9]) ) # One label > >> > >> (?:\.(?1))*+ # More labels > >> \.? # Root domain name > >> $/iDx > >> > >> This rule matches only<label> and<label>. but > >> not<label>.<label>... > >> > >> I don't know what wrong with it. > >> > >> Thank you. > >> > > > > > > > > I think trying to do all of this in one regex will prove more trouble > > than it's worth. Maybe breaking it down into something like this: > > > > <?php > > $domain = "www.ashleysheridan.co.uk"; > > $valid = false; > > > > $tlds = array('aero', 'asia', 'biz', 'cat', > > 'com', 'coop', 'edu', 'gov', > > 'info', 'int', 'jobs', 'mil', 'mobi', > > 'museum', 'name', 'net', 'org', > > 'pro', 'tel', 'travel', 'xxx', 'ac', > > 'ad', 'ae', 'af', 'ag', 'ai', 'al', > > 'am', 'an', 'ao', 'aq', 'ar', > > 'as', 'at', 'au', 'aw', 'ax', 'az', > > 'ba', > > 'bb', 'bd', 'be', 'bf', 'bg', > > 'bh', 'bi', 'bj', 'bm', 'bn', 'bo', > > 'br', > > 'bs', 'bt', 'bv', 'bw', 'by', > > 'bz', 'ca', 'cc', 'cd', 'cf', 'cg', > > 'ch', > > 'ci', 'ck', 'cl', 'cm', 'cn', > > 'co', 'cr', 'cu', 'cv', 'cx', 'cy', > > 'cz', > > 'de', 'dj', 'dk', 'dm', 'do', > > 'dz', 'ec', 'ee', 'eg', 'er', 'es', > > 'et', > > 'eu', 'fi', 'fj', 'fk', 'fm', > > 'fo', 'fr', 'ga', 'gb', 'gd', 'ge', > > 'gf', > > 'gg', 'gh', 'gi', 'gl', 'gm', > > 'gn', 'gp', 'gq', 'gr', 'gs', 'gt', > > 'gu', > > 'gw', 'gy', 'hk', 'hm', 'hn', > > 'hr', 'ht', 'hu', 'id', 'ie', 'il', > > 'im', > > 'in', 'io', 'iq', 'ir', 'is', > > 'it', 'je', 'jm', 'jo', 'jp', 'ke', > > 'kg', > > 'kh', 'ki', 'km', 'kn', 'kp', > > 'kr', 'kw', 'ky', 'kz', 'la', 'lb', > > 'lc', > > 'li', 'lk', 'lr', 'ls', 'lt', > > 'lu', 'lv', 'ly', 'ma', 'mc', 'md', > > 'me', > > 'mg', 'mh', 'mk', 'ml', 'mm', > > 'mn', 'mo', 'mp', 'mq', 'mr', 'ms', > > 'mt', > > 'mu', 'mv', 'mw', 'mx', 'my', > > 'mz', 'na', 'nc', 'ne', 'nf', 'ng', > > 'ni', > > 'nl', 'no', 'np', 'nr', 'nu', > > 'nz', 'om', 'pa', 'pe', 'pf', 'pg', > > 'ph', > > 'pk', 'pl', 'pm', 'pn', 'pr', > > 'ps', 'pt', 'pw', 'py', 'qa', 're', > > 'ro', > > 'rs', 'ru', 'rw', 'sa', 'sb', > > 'sc', 'sd', 'se', 'sg', 'sh', 'si', > > 'sj', > > 'sk', 'sl', 'sm', 'sn', 'so', > > 'sr', 'st', 'su', 'sv', 'sy', 'sz', > > 'tc', > > 'td', 'tf', 'tg', 'th', 'tj', > > 'tk', 'tl', 'tm', 'tn', 'to', 'tp', > > 'tr', > > 'tt', 'tv', 'tw', 'tz', 'ua', > > 'ug', 'uk', 'us', 'uy', 'uz', 'va', > > 'vc', > > 've', 'vg', 'vi', 'vn', 'vu', > > 'wf', 'ws', 'ye', 'yt', 'za', 'zm', > > 'zw', ); > > > > > > if(strlen($domain<= 253)) > > { > > $labels = explode('.', $domain); > > if(in_array($labels[count($labels)-1], $tlds)) > > { > > for($i=0; $i<count($labels) -1; $i++) > > { > > if(strlen($labels[$i])<= 63&& (!preg_match('/^[a-z0-9][a-z0-9 > > \-]*?[a-z0-9]$/', $labels[$i]) || preg_match('/^[0-9]+$/', > > $labels[$i]) )) > > { > > $valid = false; > > break; // no point continuing if one label is wrong > > } > > else > > { > > $valid = true; > > } > > } > > } > > } > > > > var_dump($valid); > > > > > > This matches the last label with a TLD, and each label thereafter > > against the standard a-z0-9 and hyphen rule as indicated in the > > preferred characters allowed in a label (LDH rule), with the start and > > end character in a label isn't a hyphen (oddly enough it doesn't mention > > starting with a digit!) > > > > Also, each label is checked to ensure it doesn't run over 63 characters, > > and the whole thing isn't over 253 characters. Lastly, each label is > > checked to ensure it doesn't completely consist of digits. > > > > I've tested it only with my domain so far, but it should work fairly > > well. As I said before, I couldn't think of a way to do it all with one > > regex. It could probably be done, but would you really want to create a > > huge and difficult to read/understand expression just because it's > > possible? > > > > Thanks, > > Ash > > http://www.ashleysheridan.co.uk > > > > > > > > Thank you for replying, Ash. > > I know it may better to pre-deal it with explode()-like, and then we > will get a less complex regular express. But I just want to know what > the problem in my Regular express. > > And the code you've offered, I don't like the idea of a limited set of > suffix, for when it may be updated some times. I just want to do format > validation, not content validation. > > And the regular express itself, yes it is complex, but I've checked it > times very carefully -- letter by letter -- I just don't understand > what's wrong with it. Or there is some bug in PCRE engine? The list there is limiting it to the current valid TLD's. That's correct, and is what a proper validator should do. You can always add new ones to the array as necessary. Thanks, Ash http://www.ashleysheridan.co.uk