Matching Text Regular Expression.

awohld has asked for the wisdom of the Perl Monks concerning the following question:

I have some lines javascript that I'm trying to parse the data out of and store in an array. I need just the information inside the single quotes. If there is a "|" in the single quotes, I just need the text to the left of the pipe. Below is my try at the code, what am I doing wrong?

'Central|Central Illinois', should be stored as a liste element with value Central

Update: I figured it out, my regex should be: my @cities = $test =~ m/'(.*?)[\||']/g;
Is this the right way to do it?

#!/usr/bin/perl -w

use strict;
use Data::Dumper;

my $test = qq[
cities = new Array (

'Alabama',
'Albuquerque',
'Bakersfield',
'Boise',
'Central|Central Illinois',
'Chicago',
'DesMoines',
'EastTennessee',
'ElPaso',
'Fargo',
'Fresno',
'GulfCoast',
'WashBalt|Washington-Baltimore',
];


my @cities = $test =~ m/'(.*?)|.?'/g;

print Dumper \@cities;
[download]

List should have:

Alabama
Albuquerque
Bakersfield
Boise
Central
Chicago
DesMoines
EastTennessee
ElPaso
Fargo
Fresno
GulfCoast
WashBalt
[download]

Comment on Matching Text Regular Expression. Select or Download Code

Replies are listed 'Best First'.
Re: Matching Text Regular Expression. by Tanktalus (Canon) on Nov 06, 2006 at 21:58 UTC
Close. What you have obviously works, but isn't quite what you want. At least, not precisely. `my @cities = $test =~ m/'(.*?)[\|']/g;` [download] Inside a character class (the stuff in the square brackets, `[]`), the \| doesn't have a special meaning as it does outside. So you don't need to escape it. Because the character class is always a "this character OR this character OR ..." set, you don't need a special character for "OR" - it's implied. And thus we have the two characters we're looking for as a termination: \| and '. Good luck!	[reply] [d/l] [select]
Re: Matching Text Regular Expression. by suaveant (Parson) on Nov 06, 2006 at 21:59 UTC
First off, the pipe character is special in regular expressions so you need to escape it `\\|`, second, your regular expression REQUIRES a pipe to be in the match... third you only allow one character after the pipe... It works better like this `my @cities = $test =~ m/^'([^'\|]+)/gm;` [download] the m modifier means match ^ to the beginning of any line, not just the string. So it matches a single quote at the front of a line and captures all characters after it that are not a pipe or a single quote. - Ant - Some of my best work - (1 2 3)	[reply] [d/l] [select]
Re: Matching Text Regular Expression. by runrig (Abbot) on Nov 06, 2006 at 21:58 UTC
'\|' is a regex metacharacter (see perlre). You need to put a backslash ('\') in front of it if you want to match a pipe ('\|').	[reply]