Strange ruby behaviour with __FILE__ constant?

Question

Hi I have been testing some very basic things in ruby and discover the following.

If i put in a file called xxxx.rb in this path "C:\Documents and Settings\Desktop\xxxx.rb"

puts __FILE__

and invoke this ruby file in a command line WITHOUT preceding ruby the output is the following

C:/Documents and Settings/Desktop/xxxx.rb

but if i invoke the xxxx.rb file with ruby (ruby xxxx.rb) in the command like the output is the following:

xxxx.rb

Why is that difference?? Thanks

PD: I'M ON WINDOWS XP SP3

RUBY VERSION: 1.8.6

Answer 1

I'm guessing that when you just double click on the file, the absolute path gets passed. You should achieve the same effect by calling it like:

ruby C:/Documents and Settings/Desktop/xxxx.rb

Answer 2

What you want is to expand the path properly:

# Affected by the current working directory, etc.
puts __FILE__

# Always an absolute path
puts File.expand_path(__FILE__, Dir.getwd)

This takes your current working directory into account.