From: Gavin Sinclair <gsinclair@...>
Date: 2004-06-27T09:37:24+09:00
Subject: Re: Writing UNIX 'wc' program

A couple of tips.

* ARGF is your friend when it comes to input; it is a virtual file
  that gets all input from named files or all from STDIN.

* 'unless' is a substitute for 'if not'.

* 'puts' is worth knowing about (I use 'printf' 1% of the time):

    puts "Word count: " + data.split(/\s/).length
    puts "Longest Line Length: #{line_length}"

* As far as elegance goes, see how you like this:

    longest_length = data.split(/\n/).map { |l| l.length }.max

  The way you've done it will perform better though, I expect.

Cheers,
Gavin
   

On Sunday, June 27, 2004, 10:03:02 AM,  wrote:

> ----- Beginning of Program -----

> #!/bin/env ruby

> # Read input from stdin only if not a tty. The only reason I gave such a
> # constraint here was just to see that I could do it. It's one of the
> # first things I do in learning a new language
> if not STDIN.tty?
>     data = STDIN.read
> end

> exit if not data


> # PRINT THE WORD COUNT

> # I'm wondering if there's an easier way to do this. It would
> # be nice of the String::count method accepted regex patterns
> # and not just strings.

> # As it stands, this method creates a seperate array of words
> # for which I get the count of. I would've rather done this
> # without the extra overhead but I guess it's no big deal: it works!
> printf("Word Count: %d\n", data.split(/\s/).length)


> # GET THE LENGTH OF THE LONGEST LINE

> # If there's a more elegant solution than what I have below, I'm all
> # ears
> line_length = 0
> data.split(/\n/).each do |line|
>     line_length = line.length if line_length < line.length
> end

> printf("Longest Line Length: %d\n", line_length)

> ----- End of Program -----