From: Matthew Smillie <M.B.Smillie@...>
Date: 2006-06-18T02:07:08+09:00
Subject: Re: Downloading Image

On Jun 17, 2006, at 17:27, Doug Bromley wrote:

> Hello again
>
> As an extension on my previous image problem I can't even successfully
> download images from a URL location.  I though tthe following  
> simple GET
> request along with writing the result to a file would work but it  
> mangles
> the image and makes it unreadable.
>
> Net::HTTP.start("www.example.com") do |http|
>  resp = http.get("/images/logo.gif")
>  outfile = open("C:/logo.gif", "w")
>  outfile.write(resp.body)
>  outfile.close
> end
>
> Have I done something wrong here?  Can anyone see what I'm doing  
> wrong?

On Windows you need to write certain files in 'binary' mode.  The  
appropriate mode strings are documented in the IO class:

http://www.ruby-doc.org/core/classes/IO.html

Also, the common idiom for writing is generally like this:

open("somefile.etc", 'wb') { |file|
   file.write(...)
}

This is done in order to ensure that if there's an exception after  
you open the file (ferinstance, writing when the disk is full, or in  
a place you don't have write permissions), that the file is still  
closed.  You could do the exception handling yourself, of course, but  
this is a convenient concise way of doing things.

Hope that helps,
matthew smillie.