iPhone - Reg Exp for url validity - iphone

Question

I have a chat view, where users can send urls to one another.
In case of a url, I want to let the user press on the link and open a web view.
I'm using IFTweetLabel which uses RegexKitLite.
Currently the only support available is if the url starts with http/https.
I want to support links without the http, for example : www.nytimes.com , and even without the "www" , nytimes.com. (and bunch of other extentions).
This is the http/s prefix reg exp :
#"([hH][tT][tT][pP][sS]?:\\/\\/[^ ,'\">\\]\\)]*[^\\. ,'\">\\]\\)])
Can someone tell me the other regular expressions I need to answer my other requirements.
I tried using This one, but adding it to objective c code generates a lot of issues.
Thanks

Answer 1

The following is John Grubers URL Matching Regex:
(?i)\b(?:[a-z][\w-]+:(?:/{1,3}|[a-z0-9%])|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:'".,<>?«»“”‘’])
The following is a regex I came up with by blending a few other regexes I had around and a good chunk of Grubers regex:
(?i)\b(?:(?:[a-z][\w\-]+://(?:\S+?(?::\S+?)?\#)?)|(?:(?:[a-z0-9\-]+\.)+[a-z]{2,4}))(?:[^\s()<>]+|\((?:[^\s()<>]+|(?:\([^\s()<>]*\)))*\))*(?<![\s`!()\[\]{};:'".,<>?«»“”‘’])
The following is a sample program that demonstrates, via RegexKitLite, what each regex matches against the sample text of:
Did you see
http://www.stackoverflow.com? Or
http://www.stackoverflow.com/?
And then there is
www.stackoverflow.com/, along with
www.stackoverflow.com/index.
Maybe something like stackoverflow.com
with extra stackoverflow.com? Or
"stackoverflow.com"?
Perhaps jobs.stackoverflow.com, or
'http://twitter.com/#!/CHOCKENBERRY',
the CHOCKLOCK!!
File
#file:///Users/johne/rkl/rkl.html#RegexKitLiteCookbook?
Maybe
http://www.yahoo.com/index///i.html!
http://www.yahoo.com/////xyz.html?!
The code:
#import <Foundation/Foundation.h>
#import "RegexKitLite.h"
int main(int argc, char *argv[]) {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSString *urlRegex = #"(?i)\\b(?:(?:[a-z][\\w\\-]+://(?:\\S+?(?::\\S+?)?\\#)?)|(?:(?:[a-z0-9\\-]+\\.)+[a-z]{2,4}))(?:[^\\s()<>]+|\\((?:[^\\s()<>]+|(?:\\([^\\s()<>]*\\)))*\\))*(?<![\\s`!()\\[\\]{};:'\".,<>?«»“”‘’])";
// John Gruber's URL matching regex from http://daringfireball.net/2010/07/improved_regex_for_matching_urls
NSString *gruberURLRegex = #"(?i)\\b(?:[a-z][\\w-]+:(?:/{1,3}|[a-z0-9%])|www\\d{0,3}[.]|[a-z0-9.\\-]+[.][a-z]{2,4}/)(?:[^\\s()<>]+|\\(([^\\s()<>]+|(\\([^\\s()<>]+\\)))*\\))+(?:\\(([^\\s()<>]+|(\\([^\\s()<>]+\\)))*\\)|[^\\s`!()\\[\\]{};:'\".,<>?«»“”‘’])";
NSString *urlString = #"Did you see http://www.stackoverflow.com? Or http://www.stackoverflow.com/?\n\nAnd then there is www.stackoverflow.com/, along with www.stackoverflow.com/index.\n\nMaybe something like stackoverflow.com with extra stackoverflow.com? Or \"stackoverflow.com\"?\n\nPerhaps jobs.stackoverflow.com, or 'http://twitter.com/#!/CHOCKENBERRY', the CHOCKLOCK!!\n\nFile #file:///Users/johne/rkl/rkl.html#RegexKitLiteCookbook?\n\nMaybe http://www.yahoo.com/index///i.html! http://www.yahoo.com/////xyz.html?!";
NSLog(#"String :\n\n%#\n\n", urlString);
NSLog(#"Matches: %#\n", [urlString componentsMatchedByRegex:urlRegex]);
NSLog(#"Gruber URL Regex Matches: %#\n", [urlString componentsMatchedByRegex:gruberURLRegex]);
[pool release]; pool = NULL;
return(0);
}
Compile with:
shell% gcc -o url url.m RegexKitLite.m -framework Foundation -licucore
When run:
shell% ./url
2011-05-27 20:32:58.204 url[25520:903] String :
Did you see http://www.stackoverflow.com? Or http://www.stackoverflow.com/?
And then there is www.stackoverflow.com/, along with www.stackoverflow.com/index.
Maybe something like stackoverflow.com with extra stackoverflow.com? Or "stackoverflow.com"?
Perhaps jobs.stackoverflow.com, or 'http://twitter.com/#!/CHOCKENBERRY', the CHOCKLOCK!!
File #file:///Users/johne/rkl/rkl.html#RegexKitLiteCookbook?
Maybe http://www.yahoo.com/index///i.html! http://www.yahoo.com/////xyz.html?!
2011-05-27 20:32:58.211 url[25520:903] Matches: (
"http://www.stackoverflow.com",
"http://www.stackoverflow.com/",
"www.stackoverflow.com/",
"www.stackoverflow.com/index",
"stackoverflow.com",
"stackoverflow.com",
"stackoverflow.com",
"jobs.stackoverflow.com",
"http://twitter.com/#!/CHOCKENBERRY",
"file:///Users/johne/rkl/rkl.html#RegexKitLiteCookbook",
"http://www.yahoo.com/index///i.html",
"http://www.yahoo.com/////xyz.html"
)
2011-05-27 20:32:58.213 url[25520:903] Gruber URL Regex Matches: (
"http://www.stackoverflow.com",
"http://www.stackoverflow.com/",
"www.stackoverflow.com/",
"www.stackoverflow.com/index",
"http://twitter.com/#!/CHOCKENBERRY",
"file:///Users/johne/rkl/rkl.html#RegexKitLiteCookbook",
"http://www.yahoo.com/index///i.html",
"http://www.yahoo.com/////xyz.html"
)
EDIT 2011/05/27: Made a minor change to the regex to fix a problem where it wasn't matching ( ) parenthesis correctly.
EDIT 2011/05/27: Found some additional corner cases that the regex above didn't handle well. Updated regex:
(?i)\b(?:[a-z][\w\-]+://(?:\S+?(?::\S+?)?\#)?)?(?:(?:(?<!:/|\.)(?:(?:[a-z0-9\-]+\.)+[a-z]{2,4}(?![a-z]))|(?<=://)/))(?:(?:[^\s()<>]+|\((?:[^\s()<>]+|(?:\([^\s()<>]*\)))*\))*)(?<![\s`!()\[\]{};:'".,<>?«»“”‘’])
... as an Obj-C string:
#"(?i)\\b(?:[a-z][\\w\\-]+://(?:\\S+?(?::\\S+?)?\\#)?)?(?:(?:(?<!:/|\\.)(?:(?:[a-z0-9\\-]+\\.)+[a-z]{2,4}(?![a-z]))|(?<=://)/))(?:(?:[^\\s()<>]+|\\((?:[^\\s()<>]+|(?:\\([^\\s()<>]*\\)))*\\))*)(?<![\\s`!()\\[\\]{};:'\".,<>?«»“”‘’])";
The OP also asked for how to make sure the trailing TLD was "valid". Here's the same regex, in Obj-C string form, with all the the currently valid TLDs (as of 2011/05/27):
#"(?i)\\b(?:[a-z][\\w\\-]+://(?:\\S+?(?::\\S+?)?\\#)?)?(?:(?:(?<!:/|\\.)(?:(?:[a-z0-9\\-]+\\.)+(?:(ac|ad|ae|aero|af|ag|ai|al|am|an|ao|aq|ar|arpa|as|asia|at|au|aw|ax|az|ba|bb|bd|be|bf|bg|bh|bi|biz|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cat|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|com|coop|cr|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|edu|ee|eg|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gg|gh|gi|gl|gm|gn|gov|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|info|int|io|iq|ir|is|it|je|jm|jo|jobs|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|mil|mk|ml|mm|mn|mo|mobi|mp|mq|mr|ms|mt|mu|museum|mv|mw|mx|my|mz|na|name|nc|ne|net|nf|ng|ni|nl|no|np|nr|nu|nz|om|org|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|pro|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|tel|tf|tg|th|tj|tk|tl|tm|tn|to|tp|tr|travel|tt|tv|tw|tz|ua|ug|uk|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|xn--0zwm56d|xn--11b5bs3a9aj6g|xn--3e0b707e|xn--45brj9c|xn--80akhbyknj4f|xn--90a3ac|xn--9t4b11yi5a|xn--clchc0ea0b2g2a9gcd|xn--deba0ad|xn--fiqs8s|xn--fiqz9s|xn--fpcrj9c3d|xn--fzc2c9e2c|xn--g6w251d|xn--gecrj9c|xn--h2brj9c|xn--hgbk6aj7f53bba|xn--hlcj6aya9esc7a|xn--j6w193g|xn--jxalpdlp|xn--kgbechtv|xn--kprw13d|xn--kpry57d|xn--lgbbat1ad8j|xn--mgbaam7a8h|xn--mgbayh7gpa|xn--mgbbh1a71e|xn--mgbc0a9azcg|xn--mgberp4a5d4ar|xn--o3cw4h|xn--ogbpf8fl|xn--p1ai|xn--pgbs0dh|xn--s9brj9c|xn--wgbh1c|xn--wgbl6a|xn--xkc2al3hye2a|xn--xkc2dl3a5ee0h|xn--yfro4i67o|xn--ygbi2ammx|xn--zckzah|xxx|ye|yt|za|zm|zw))(?![a-z]))|(?<=://)/))(?:(?:[^\\s()<>]+|\\((?:[^\\s()<>]+|(?:\\([^\\s()<>]*\\)))*\\))*)(?<![\\s`!()\\[\\]{};:'\".,<>?«»“”‘’])";

Answer 2

This will match both http://example.org and www.example.org.
#"(([hH][tT][tT][pP][sS]?:\\/\\/|www\\.)[^ ,'\">\\]\\)]*\\.[^\\. ,'\">\\]\\)]{2,6})
Although i added a "match group", so check the match/search result returned by the RegExp so the right parameters are re-inserted in the right place.
If you could post the entire code snippet, it would be easier.
RegExp explanation:
(
(
[hH][tT][tT][pP][sS]?:\/\/ # Match HTTP/http (and hTtP :)
| # OR
www\. # www<literal DOT>
)
[^ ,'\">\]\)]* # Match at least 1 character that are not any of space, comma, apostrophe, quotation mark, "more than", "right square bracket", "right parenthese"
\. # Match <literal DOT>
[^\. ,'\">\]\)]{2,6} # Match 2-6 characters that are not any of dot, space, comma, apostrophe, quotation mark, "more than", "right square bracket", "right parenthese"
)

Answer 3

You don't want to use a regular expression for this.
You want an NSDataDetector, and it'll find them all for you.