Remove "www", "http://" from string

Question

How can I remove "www", "http://", "https://" from strings using Ruby?

I tried this but it didn't work:

s.gsub('/(?:http?:\/\/)?(?:www\.)?(.*)\/?$/i', '')

Here what I'm doing in Rails:

<%= auto_link(job.description) do |url| url.truncate(25).gsub('http://', '') end %>

Url are truncated, but my goal is to remove the beginning of the links, such as "www" or "http://" so the link would look like "google.com/somepage/d...", not like "http://google.com/some..."

[`String#sub`](http://www.ruby-doc.org/core-1.9.3/String.html#method-i-sub-21) — Michael Berkowski, Apr 20 '12 at 17:55
I tried gsub with some regexes I found but nothing worked. For example this: s.gsub('/(?:http?:\/\/)?(?:www\.)?(.*)\/?$/i', '') — Martin Petrov, Apr 20 '12 at 17:59
What is the bigger problem you're trying to solve? Do you want to redirect "www.mydomain.com" to "mydomain.com"? — CambridgeMike, Apr 20 '12 at 18:02
@MartinPetrov I've edited you question to include that, but please edit it further to include example input/output that didn't work as you expected. — Andrew Marshall, Apr 20 '12 at 18:03

SwiftMango · Accepted Answer · 2012-04-20T18:35:35.390

44

s = s.sub(/^https?\:\/\//, '').sub(/^www./,'')

If you don't want to use s =, you should use sub!s instead of all subs.

The problems with your code are:

Question mark always follows AFTER an optional character
Always replace one pattern in a sub. You can "chain up" multiple operations.
Use sub instead of gsub and ^ in the beginning of Regexp so it only replaces the http:// in the beginning but leaves the ones in the middle.

edited Apr 20 '12 at 18:35

answered Apr 20 '12 at 18:30

SwiftMango

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Awesome answer. Here's an upgrade: `s.(/^https?\:\/\/(www.)?/,'')` ... and `.sub(/\/.*$/,'')` to remove the path – Nav Oct 16 '12 at 04:20
why `sub` instead of `gsub`? – Rafael Costa Mar 21 '19 at 16:16

Josh · Answer 2 · 2015-11-13T15:12:14.833

5

This method should catch all 3 variations:

def strip_url(url)
  url.sub!(/https\:\/\/www./, '') if url.include? "https://www."

  url.sub!(/http\:\/\/www./, '')  if url.include? "http://www."

  url.sub!(/www./, '')            if url.include? "www."

  return url
end

strip_url("http://www.google.com")
   => "google.com" 
strip_url("https://www.facebook.com")
   => "facebook.com" 
strip_url("www.stackoverflow.com")
  => "stackoverflow.com"

edited Nov 13 '15 at 15:12

answered Apr 20 '12 at 19:11

Josh

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@JuliusMarkūnas strip_url("stackoverflow.com") still returns the expected output. What did you expect to be different? – Josh Oct 29 '13 at 17:25
@JuliusMarkūnas What does that return that is unexpected? – Josh Nov 05 '13 at 17:28
It does not remove http from beginning of url `strip_url("http://stackoverflow.com") #=> "http://stackoverflow.com" ` – Julius Markūnas Nov 06 '13 at 08:02

score 1 · Answer 3 · answered Nov 13 '15 at 10:05

def strip_url(target_url)
  target_url.gsub("http://", "")
            .gsub("https://", "")
            .gsub("www.", "")
end

strip_url("http://www.google.com")
 => "google.com" 
strip_url("https://www.google.com")
 => "google.com" 
strip_url("http://google.com")
 => "google.com"
strip_url("https://google.com")
 => "google.com" 
strip_url("www.google.com")
 => "google.com"

Remove "www", "http://" from string

3 Answers3

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