From: Florian Gross <flgr@...>
Date: 2005-01-12T21:11:17+09:00
Subject: Re: Comparing two files for equality

Edgardo Hames wrote:

> Hi everybody,

Moin.

> I tried to implement a program that
> compares two files for equality. I came up with the following trivial
> solution
> 
> puts (IO.readlines file[0]) == (IO.readlines file[1])
> 
> Have you got any other suggestions?

Not much different:

def files_equal?(*files)
   files.map do |file|
     File.size file
   end.uniq.size <= 1 and
   files.map do |file|
     File.read file
   end.uniq.size <= 1
end

This ought to be slightly faster in the average case.

Other optimizations would be reading the files line-wise in parallel and 
bailing out as soon as one of the lines differs.