From: "Hal E. Fulton" <hal9000@...>
Date: 2001-12-30T08:51:30+09:00
Subject: [ruby-talk:29669] Re: comma-delimited to an array

----- Original Message -----
From: Dash Riprock <dazh_ribrogg@yahoo.com>
Newsgroups: comp.lang.ruby
To: ruby-talk ML <ruby-talk@ruby-lang.org>; <undisclosed-recipients: ;>
Sent: Saturday, December 29, 2001 5:37 PM
Subject: [ruby-talk:29668] comma-delimited to an array


> I've got a file in which each line has comma-delimited items. A
> sample might look like this:
>
> num,date,time,orig,type,action,rule,iface
> 1,28Dec2001,23:59:51,121.210.49.22,log,accept,16,eth-s1p2c0
> 2,28Dec2001,23:59:44,121.210.48.11,log,drop,20,eth-s1p1c0
> 3,28Dec2001,23:59:57,121.210.49.22,log,accept,16,eth-s1p1c0
>
> Because the order of the items may *vary* from day to day, I want to
> treat each line as an array.
>
> But the question is, as I read each line, how do I convert that
> single line into an array?

Here's a quick and dirty way. It assumes 1) everything is a string
and nothing has quotes on it yet (per your example) and
2) you don't mind using eval.

arr = eval ("[" + line.chomp.split(",").collect {|x| '"' + x +
'"'}.join(",") + "]")

Warning: I haven't tested this.

The translation for the newbie:
- remove the newline
- get an array of items delimited by commas
- get another array consisting of all those same
  elements but surrounded by quotes
- create a new string by joining using commas
- surround the new string with brackets
- eval to get an array of strings

Hope this helps.

Note that some people are really paranoid about eval.
I think in a case like this, it's a non-issue. (Someone
will probably prove me wrong.)

Also note that the problem gets more complex if you
start embedding commas and quotes inside the data
items; if you want to treat some of them as integers or
other things; and so on.

Cheers,
Hal Fulton