If we want to golf it, it would probably just be

  lines = IO.readlines ARGV[0]
  File.write ARGV[1], lines.sort.join('\n')

certainly more readable than the C++ even if you're unfamiliar with ruby.

Well, if you really want to golf it, you can just write:

  File.write ARGV[1], IO.readlines(ARGV[0]).sort.join('\n')

;)

You're fired.

    IO.write(ARGV[1], ARGF.lines.sort.join)

Here's the shortest I've gotten after looking at some of the comments:

  IO.write$*.pop,ARGF.lines.sort.join

And yes, it does work even without the space between `write` and `$*`.

Also after testing, I realized the ('\n') is not required for join. When you call 'lines', it still has the '\n' character in the string, and when you join, it defaults to join without a delimiter, so it's putting them back together with the newline still there.

Wow, this is really sweet and esoteric (didn't know about ARGF) - but, reading the docs for ARGF, wouldn't it also try to ready from ARGV[1]?

Maybe this would fix it:

  IO.write(ARGV.pop, ARGF.lines.sort.join('\n'))

Yes, good catch. join('\n') is wrong though - IO#lines preserves newlines, the default join is the empty string, and you meant "\n" :)

:)

I believe you still need to join on newline, the default is space. However you can save a couple characters by using `$*` instead of ARGV.

Also, trim out the space between the arguments and kill the parenthesis for the optimal golfing.

Is

> File.write ARGV[1], (IO.readlines ARGV[0]).sort.join('\n')

not valid Ruby?

  File.open(ARGV[1], 'w') { |file| file.write(File.read(ARGV[0]).lines.sort.join) }

http://stackoverflow.com/questions/8278680/ruby-undefined-me...

The thing is in ruby you are already in main method so there's no need to declare main function as an entry point. The main reason that the c++ version the code is longer has some historical/performance related issues! In c++11 it could've been with smaller standard library at design but that could break the old codes! Although obviously, "Little code =! Better code". What you want to achieve is actually more important. Btw, C++ as a scripting language? at first you might think that way but truly that's a big lie :)

I'm not arguing with that ;)

BTW, I would never use Ruby for anything that needs performance, but for ease of use and readability it's really great.

Now that's the succinctness I'd expect from an actual scripting language

Except that's not what the C++ code does. The C++ reads and writes from files given as command line arguments.

Fixed

Thanks. I know enough ruby to be dangerous so didn't know if more needed to be done than that simple substitution.

Or:

   ruby -e 'puts ARGF.sort' file.txt

Also, this reads stdin if the argument is omitted.