4 ms·

I was using a monster of a regex for validating URLs in a Ruby (Sinatra) app, and it wasn't even looking in unstructured text). Found it at http://snipplr.com/v

by ehsanul 17y ago

I was using a monster of a regex for validating URLs in a Ruby (Sinatra) app, and it wasn't even looking in unstructured text). Found it at http://snipplr.com/view/6889/regular-expressions-for-uri-validationparsing/ http://snipplr.com/view/6889/regular-expressions-for-uri-val... /^(https?):\/\/((?:[a-z0-9.\-]|%[0-9A-F]{2}){3,})(?::(\d+))?((?:\/(?:[a-z0-9\-._~!$&'()+,;=:@]|%[0-9A-F]{2})))(?:\?((?:[a-z0-9\-._~!$&'()+,;=:\/?@]|%[0-9A-F]{2})))?(?:#((?:[a-z0-9\-._~!$&'()+,;=:\/?@]|%[0-9A-F]{2})*))?$/i Yeah, more involved. Though it parses it into the url parts, and it does work.

wingo 17y ago
It looks like line noise. But it's funny though, I can read regexps better than I can read formal semantics. Having tried once this evening to read http://matt.might.net/papers/might2007diss.pdf http://matt.might.net/papers/might2007diss.pdf, regexps are refreshing :)
- mahmud 17y ago
  Please do not link to random papers on semantics, you don't know whose weekend you might ruin. Horrible nerd-snipping there; I grok half of the paper, and have no choice but to study the formal semantics of the other half :-(
- PStamatiou 17y ago
  Matt Might (author of linked PDF) was my Computer Science TA four or five years ago at Georgia Tech... for a java class. small world haha
riffraff 17y ago
what is wrong with URI.parse in the stdlib? the articles' re goes out of url validation to get urlish things in free text, (e.g. " lokk at http://goo.com/bat http://goo.com/bat, lovely" the comma would actually be part of a valid url, but the regex tries to detect this. Yet, for url validation ruby's lib is enough, I believe.
- ehsanul 17y ago
  Well, with URI.parse, you can send in a ftp uri, or just "something.com" (which is parsed as just a path). So not really what I need from URL validation. If there's something else I'm missing, I'm happy to know. Edit: And btw, for an industrial-strength Ruby URI library (to replace the standard library), check out Addressable: http://addressable.rubyforge.org/ http://addressable.rubyforge.org/
  - riffraff 17y ago
    try URI.regexp('http') :)

by ehsanul 17y ago

wingo 17y ago

It looks like line noise. But it's funny though, I can read regexps better than I can read formal semantics. Having tried once this evening to read http://matt.might.net/papers/might2007diss.pdf http://matt.might.net/papers/might2007diss.pdf, regexps are refreshing :)

mahmud 17y ago
Please do not link to random papers on semantics, you don't know whose weekend you might ruin. Horrible nerd-snipping there; I grok half of the paper, and have no choice but to study the formal semantics of the other half :-(
PStamatiou 17y ago
Matt Might (author of linked PDF) was my Computer Science TA four or five years ago at Georgia Tech... for a java class. small world haha

riffraff 17y ago

what is wrong with URI.parse in the stdlib? the articles' re goes out of url validation to get urlish things in free text, (e.g. " lokk at http://goo.com/bat http://goo.com/bat, lovely" the comma would actually be part of a valid url, but the regex tries to detect this. Yet, for url validation ruby's lib is enough, I believe.

ehsanul 17y ago
Well, with URI.parse, you can send in a ftp uri, or just "something.com" (which is parsed as just a path). So not really what I need from URL validation. If there's something else I'm missing, I'm happy to know. Edit: And btw, for an industrial-strength Ruby URI library (to replace the standard library), check out Addressable: http://addressable.rubyforge.org/ http://addressable.rubyforge.org/
- riffraff 17y ago
  try URI.regexp('http') :)