Re: Help: Validate Domain Name by Regular Express

On Sun, 2011-01-09 at 11:44 +0800, WalkinRaven wrote: > Right, RFC 1034 allow valid endless . parts, till the sum length is over > 255. > > On 01/09/2011 01:21 AM, TR Shaw wrote: > > On Jan 8, 2011, at 12:09 PM, 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? > > Ash > > > > I doubt its possible since the ccTLD's have valid 3 and more dotted domain names. You > > should see .us And .uk doesn't follow the ccTLS rules for .tk for example. > > > > Now, if the purpose is to write a regex for a host name then that's a different > > story. > > > > Tom > Which is what my code does too, while also checking for label length. Thanks, Ash http://www.ashleysheridan.co.uk