From: Brian Candler <B.Candler@...>
Date: 2007-02-09T23:46:21+09:00
Subject: Re: File.open () Errno::ENOTDIR

On Fri, Feb 09, 2007 at 11:12:46PM +0900, Rebhan, Gilbert wrote:
> i have a problem with File.open =
> 
> File.open(SRCDIR<<'/'<<Dir.entries(SRCDIR).sort[2]<<'/foobar.TXT') do
> |f|
>   mymethod(x)
> end

Warning:

    string1 << string2

modifies string1 by adding the contents of string2. So here you are
modifying SRCDIR, which is probably not what you want, especially if you're
going round this in a loop.

SRCDIR='/tmp'
puts SRCDIR<<'/bar'    # '/tmp/bar'
puts SRCDIR            # '/tmp/bar'

Use + to concatenate two strings and get the result as a third,
newly-created string.

> How to get the Dirname Dir.entries(SRCDIR).sort[2] into the string
> for method File.open ?

File.open(SRCDIR + '/' + Dir.entries(SRCDIR).sort[2] + '/foobar.TXT')

or

File.open("#{SRCDIR}/#{Dir.entries(SRCDIR).sort[2]}/foobar.TXT")