How do you download a file from the web and save it locally?

I’m trying to learn Ruby. A task I’m trying to do is download a file from the web and save it locally.

I’m looking at http://ruby.bastardsbook.com/chapters/io/ and trying to implement the solution in the “Exercise: Copy Wikipedia’s front page to a file using block notation” section, but it’s not working for me. The error message I get is:

/home/jhsu/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in require': cannot load such file -- rest-client (LoadError) from /home/jhsu/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in require’
from test.rb:4:in `’

What am I missing? Would another approach be better?

Jason Hsu, Android developer wrote in post #1097902:

I'm trying to learn Ruby. A task I'm trying to do is download a file
from
the web and save it locally.

I'm looking at http://ruby.bastardsbook.com/chapters/io/ and trying to
implement the solution in the "Exercise: Copy Wikipedia's front page to
a
file using block notation" section, but it's not working for me. The
error
message I get is:

/home/jhsu/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in

`require': cannot load such file -- rest-client (LoadError)
    from

/home/jhsu/.rvm/rubies/ruby-1.9.3-p385/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in

`require'
    from test.rb:4:in `<main>'

What am I missing? Would another approach be better?

Did you install the rest-client gem?

gem install rest-client

You you don't have the gem installed Ruby can't very well load it.
Usually when you see that custom_require it assumes the name you gave in
require statement is custom since it wasn't found in the list of gems.

Did you do this chapter first?
http://ruby.bastardsbook.com/chapters/methods-and-gems/

save_path="/your/local/path/filename"

File.open(save_path, ‘wb’) do |file|

file << open(‘download_file_url’).read

end