From: Robert Klemme <shortcutter@...>
Date: 2008-09-25T03:29:48+09:00
Subject: Re: Strange ruby problem

On 24.09.2008 16:18, christoforever@gmail.com wrote:
> So i've cut the program down to about 4 lines to give the idea of
> whats going on:
> 
> num = ARGV[0]
> num2 = ARGV[1]
> puts " #{num} #{num2} \n"
> line = gets
> 
> 
> if i give the program some input from the command line it fails and
> sais " gets: No such file or directory -1"
> yet if i supply no input the program goes straight to gets. This seems
> fairly strange to me. Though when I did this:
> 
> num = ARGV[0]
> num2 = ARGV[1]
> puts " #{num} #{num2} \n"
> STDOUT.flush
> line = STDIN.gets
> 
> everything works normal. Why is this and whats going on? Thanks in
> advance

As others have said: arguments are the problem.  "gets" tries to read 
from ARGF which is basically all ARGV values interpreted as files and 
concatenated as streams.  You typically use this for poor man's cat:

ruby -e 'ARGF.each {|line| puts line}' foo bar baz

You can avoid the issue by doing

num = ARGV.shift
num2 = ARGV.shift
puts num, num2
line = gets

Cheers

	robert