From: Rob Biedenharn <Rob@...>
Date: 2010-10-04T04:19:59+09:00
Subject: Re: Puts to stream?


On Oct 3, 2010, at 2:54 PM, Terry Michaels wrote:

> I've got simple statements like so:
>
> puts "hi"
> puts "there"
> puts name
>
> Wanted to adjust it to write to IO object (a string) instead of  
> stdout.
> This is the kind of construction I'd like to use:
>
> my_out = String.new
> puts my_out "hi"
> puts my_out "there"
> puts my_out name
>
> But apparently that doesn't work. This seems to work
>
> my_out << "hi" << "\n"
> my_out << "there" << "\n"
> my_out << name << "\n"
>
> The lame part of that, though, is that it does not do the whole "check
> if there is an end-line and add one if there isn't" magic, so I have  
> to
> manually specify the newline if I want one. I tried
>
> my_out.puts "hi"
>
> But evidently that does the exact opposite of want I want.
> -- 
> Posted via http://www.ruby-forum.com/.
>

In addition to Quintus, here's a bit more depending on how far you're  
looking to go:

irb> puts "hi"
hi
=> nil
irb> require 'stringio'
=> true
irb> my_out = StringIO.new('')
=> #<StringIO:0x1e5d20>
irb> my_out.puts "hi"
=> nil
irb> my_out.string
=> "hi\n"

So you can explicitly use puts on the StringIO instance.

If you want to implicitly target your StringIO, you can:

irb> begin
?>     saved_stdout = $stdout
irb>   $stdout = my_out
irb>   puts "there"
irb> ensure
?>     $stdout = saved_stdout
irb> end
=> nil
irb> my_out.string
=> "hi\nthere\n"

Note that the ensure block puts $stdout back to where it started.

-Rob

Rob Biedenharn		
Rob@AgileConsultingLLC.com	http://AgileConsultingLLC.com/
rab@GaslightSoftware.com		http://GaslightSoftware.com/