From: Kyle Schmitt <kyleaschmitt@...>
Date: 2007-07-11T05:45:05+09:00
Subject: Re: Help: Efficient regular expression

I love regex, so it hurts me to say it, there are other ways of solving this ;)

for instance:

string = "root     14051 14033  3 08:39 pts/2    00:00:00 /bin/bash"
number = string.split[1]
program=string.split.last


now regexes!

string = "root     14051 14033  3 08:39 pts/2    00:00:00 /bin/bash"
number=string[/[0-9]+/]
program=string[/[a-z\/]+$/]

You know you can get values out of an array with the [] operator.
Well you can get strings out of strings that same way, and it works
with regexes!

string[/[0-9]+/] will return the first match of 1 or more numbers

Here's the magic use [ ] inside of a regular expression to create your
own groups.  Individual characters in there are included in the group,
and ranges may be included using the -.  so a-b is
abcdefghijklmnopqrstuvwxyz.
The + afterwards means 1 or more times.
What if you want _exactly 5 consecutive numbers? use the {}
string[/[0-9]{5}/]
ranges also work here
string[/[0-9]{3-5}/] would match 3, 4 or 5 digit numbers

and
string[/[a-z\/]+$/] will match a text string containing the forward
slash at the end.  The $ is a special char to represent the end of a
line, and since / is a special char itself, it needed to be escaped
with a \.

BUT it could even be easier.
the [] groups, can be negative!
/[^a]*/ would match any string that did not have an a in it
/[^ ]*/ would match any string that did not have a space in it...soo
string[/[^ ]+$/] would be a good way to get the last bit.