From: Alex Gutteridge <alexg@...>
Date: 2007-11-22T14:38:14+09:00
Subject: Re: Problem printing variable with $stdout.print

On 22 Nov 2007, at 12:58, Peter Vanderhaden wrote:

> I'm a newbie to Ruby & OO programming, so please bear with me.  I
> searched the forum & didn't find anything relevant.  I want to print  
> the
> value of argv[0] to standard output, but I can't figure out the  
> syntax.
> Below is one of the ways I tried, but it obviously doesn't work.  I'd
> appreciate any advice anyone can provide, along with syntax that will
> get this to work.
> Thanks
>
>        $stdout.print "Invalid filename entered: argv[0] \n"

The literal answer to your question is:

$stdout.print "Invalid filename entered: #{argv[0]}\n"

But that's probably not what you really want. Firstly, You probably  
mean ARGV instead of argv, so:

$stdout.print "Invalid filename entered: #{ARGV[0]}\n"

But that's (very, very nearly) the same as just:

print "Invalid filename entered: #{ARGV[0]}\n"

Which in Ruby is better written as:

puts "Invalid filename entered: #{ARGV[0]}"

This is the best place to get started IMHO:

http://www.rubycentral.com/pickaxe/intro.html

Alex Gutteridge

Bioinformatics Center
Kyoto University