How to URL encode a string in Ruby

How do I URI::encode a string like:

\x12\x34\x56\x78\x9a\xbc\xde\xf1\x23\x45\x67\x89\xab\xcd\xef\x12\x34\x56\x78\x9a

to get it in a format like:

%124Vx%9A%BC%DE%F1%23Eg%89%AB%CD%EF%124Vx%9A

as per RFC 1738?

Here's what I tried:

irb(main):123:0> URI::encode "\x12\x34\x56\x78\x9a\xbc\xde\xf1\x23\x45\x67\x89\xab\xcd\xef\x12\x34\x56\x78\x9a"
ArgumentError: invalid byte sequence in UTF-8
	from /usr/local/lib/ruby/1.9.1/uri/common.rb:219:in `gsub'
	from /usr/local/lib/ruby/1.9.1/uri/common.rb:219:in `escape'
	from /usr/local/lib/ruby/1.9.1/uri/common.rb:505:in `escape'
	from (irb):123
	from /usr/local/bin/irb:12:in `<main>'

Also:

irb(main):126:0> CGI::escape "\x12\x34\x56\x78\x9a\xbc\xde\xf1\x23\x45\x67\x89\xab\xcd\xef\x12\x34\x56\x78\x9a"
ArgumentError: invalid byte sequence in UTF-8
	from /usr/local/lib/ruby/1.9.1/cgi/util.rb:7:in `gsub'
	from /usr/local/lib/ruby/1.9.1/cgi/util.rb:7:in `escape'
	from (irb):126
	from /usr/local/bin/irb:12:in `<main>'

I looked all about the internet and haven't found a way to do this, although I am almost positive that the other day I did this without any trouble at all.

str = "\x12\x34\x56\x78\x9a\xbc\xde\xf1\x23\x45\x67\x89\xab\xcd\xef\x12\x34\x56\x78\x9a".force_encoding('ASCII-8BIT')
puts CGI.escape str


=> "%124Vx%9A%BC%DE%F1%23Eg%89%AB%CD%EF%124Vx%9A"

Nowadays, you should use ERB::Util.url_encode or CGI.escape. The primary difference between them is their handling of spaces:

>> ERB::Util.url_encode("foo/bar? baz&")
=> "foo%2Fbar%3F%20baz%26"

>> CGI.escape("foo/bar? baz&")
=> "foo%2Fbar%3F+baz%26"

CGI.escape follows the CGI/HTML forms spec and gives you an application/x-www-form-urlencoded string, which requires spaces be escaped to +, whereas ERB::Util.url_encode follows RFC 3986, which requires them to be encoded as %20.

See "https://stackoverflow.com/questions/2824126/whats-the-difference-between-uri-escape-and-cgi-escape/13059657#13059657" for more discussion.

str = "\x12\x34\x56\x78\x9a\xbc\xde\xf1\x23\x45\x67\x89\xab\xcd\xef\x12\x34\x56\x78\x9a"
require 'cgi'
CGI.escape(str)
# => "%124Vx%9A%BC%DE%F1%23Eg%89%AB%CD%EF%124Vx%9A"

Taken from @J-Rou's comment

You can use Addressable::URI gem for that:

require 'addressable/uri'   
string = '\x12\x34\x56\x78\x9a\xbc\xde\xf1\x23\x45\x67\x89\xab\xcd\xef\x12\x34\x56\x78\x9a'
Addressable::URI.encode_component(string, Addressable::URI::CharacterClasses::QUERY)
# "%5Cx12%5Cx34%5Cx56%5Cx78%5Cx9a%5Cxbc%5Cxde%5Cxf1%5Cx23%5Cx45%5Cx67%5Cx89%5Cxab%5Cxcd%5Cxef%5Cx12%5Cx34%5Cx56%5Cx78%5Cx9a" 

It uses more modern format, than CGI.escape, for example, it properly encodes space as %20 and not as + sign, you can read more in "The application/x-www-form-urlencoded type" on Wikipedia.

2.1.2 :008 > CGI.escape('Hello, this is me')
 => "Hello%2C+this+is+me" 
2.1.2 :009 > Addressable::URI.encode_component('Hello, this is me', Addressable::URI::CharacterClasses::QUERY)
 => "Hello,%20this%20is%20me" 

I was originally trying to escape special characters in a file name only, not on the path, from a full URL string.

ERB::Util.url_encode didn't work for my use:

helper.send(:url_encode, "http://example.com/?a=\11\15")
# => "http%3A%2F%2Fexample.com%2F%3Fa%3D%09%0D"

Based on two answers in "https://stackoverflow.com/questions/34274838/why-is-uri-escape-marked-as-obsolete-and-where-is-this-regexpunsafe-constant";, it looks like URI::RFC2396_Parser#escape is better than using URI::Escape#escape. However, they both are behaving the same to me:

URI.escape("http://example.com/?a=\11\15")
# => "http://example.com/?a=%09%0D"
URI::Parser.new.escape("http://example.com/?a=\11\15")
# => "http://example.com/?a=%09%0D"

I created a gem to make URI encoding stuff cleaner to use in your code. It takes care of binary encoding for you.

Run gem install uri-handler, then use:

require 'uri-handler'

str = "\x12\x34\x56\x78\x9a\xbc\xde\xf1\x23\x45\x67\x89\xab\xcd\xef\x12\x34\x56\x78\x9a".to_uri
# => "%124Vx%9A%BC%DE%F1%23Eg%89%AB%CD%EF%124Vx%9A"

It adds the URI conversion functionality into the String class. You can also pass it an argument with the optional encoding string you would like to use. By default it sets to encoding 'binary' if the straight UTF-8 encoding fails.

Code:

str = "http://localhost/with spaces and spaces"
encoded = URI::encode(str)
puts encoded

Result:

http://localhost/with%20spaces%20and%20spaces

If you want to "encode" a full URL without having to think about manually splitting it into its different parts, I found the following worked in the same way that I used to use URI.encode:

URI.parse(my_url).to_s