I found this regular expression on a website. It is said to be the best URL validation expression out there and I agree. Diego Perini created it.
The problem I am facing is when trying to use it with objective-C to detect URLs on strings. I have tried using options like NSRegularExpressionAnchorsMatchLines, NSRegularExpressionIgnoreMetacharacters and others, but still no luck.
Is the expression not well formatted for Objective-C? Am I missing something? Any ideas?
I have tried John Gruber's regex, also, but it fails with some invalid URLs.
Regular Expression Explanation of expression
^ match at the beginning
//Protocol identifier
(?:
(?:https?|ftp http, https or ftp
):\/\/ ://
)? optional
// User:Pass authentication
(?:
^\s+ non white spaces, 1 or more times
(?:
:^\s* : non white spaces, 0 or more times, optionally
)?@ @
)? optional
//Private IP Addresses ?! Means DO NOT MATCH ahead. So do not match any of the following
(?:
(?!10 10 10.0.0.0 - 10.999.999.999
(?:
\.\d{1,3} . 1 to 3 digits, three times
){3}
)
(?!127 127 127.0.0.0 - 127.999.999.999
(?:
\.\d{1,3} . 1 to 3 digits, three times
){3}
)
(?!169\.254 169.254 169.254.0.0 - 169.254.999.999
(?:
\.\d{1,3} . 1 to 3 digits, two times
){2}
)
(?!192\.168 192.168 192.168.0.0 - 192.168.999.999
(?:
\.\d{1,3} . 1 to 3 digits, two times
){2}
)
(?!172\. 172. 172.16.0.0 - 172.31.999.999
(?:
1[6-9] 1 followed by any number between 6 and 9
| or
2\d 2 and any digit
| or
3[0-1] 3 followed by a 0 or 1
)
(?:
\.\d{1,3} . 1 to 3 digits, two times
){2}
)
//First Octet IPv4 // match these. Any non network or broadcast IPv4 address
(?:
[1-9]\d? any number from 1 to 9 followed by an optional digit 1 - 99
| or
1\d\d 1 followed by any two digits 100 - 199
| or
2[01]\d 2 followed by any 0 or 1, followed by a digit 200 - 219
| or
22[0-3] 22 followed by any number between 0 and 3 220 - 223
)
//Second and Third Octet IPv4
(?:
\. .
(?:
1?\d{1,2} optional 1 followed by any 1 or two digits 0 - 199
| or
2[0-4]\d 2 followed by any number between 0 and 4, and any digit 200 - 249
| or
25[0-5] 25 followed by any numbers between 0 and 5 250 - 255
)
){2} two times
//Fourth Octet IPv4
(?:
\. .
(?:
[1-9]\d? any number between 1 and 9 followed by an optional digit 1 - 99
| or
1\d\d 1 followed by any two digits 100 - 199
| or
2[0-4]\d 2 followed by any number between 0 and 4, and any digit 200 - 249
| or
25[0-4] 25 followed by any number between 0 and 4 250 - 254
)
)
//Host name
| or
(?:
(?:
[a-zu00a1-uffff0-9]+-? any letter, digit or character one or more times with optional -
)* zero or more times
[a-zu00a1-uffff0-9]+ any letter, digit or character one or more times
)
//Domain name
(?:
\. .
(?:
[a-zu00a1-uffff0-9]+-? any letter, digit or character one or more times with optional -
)* zero or more times
[a-zu00a1-uffff0-9]+ any letter, digit or character one or more times
)* zero or more times
//TLD identifier
(?:
\. .
(?:
[a-zu00a1-uffff]{2,} any letter, digit or character more than two times
)
)
)
//Port number
(?:
:\d{2,5} : followed by any digit, two to five times, optionally
)?
//Resource path
(?:
\/[^\s]* / followed by an optional non space character, zero or more times
)? optional
$ match at the end
EDIT
I think I forgot to say that I am using the expression in the following code: (partial code)
NSError *error = NULL;
NSRegularExpression *detector = [NSRegularExpression regularExpressionWithPattern:[self theRegularExpression] options:0 error:&error];
NSArray *links = [detector matchesInString:theText options:0 range:NSMakeRange(0, theText.length)];
See Question&Answers more detail:
os 
