String Matching

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

Hello all, I was wondering if I could please get some help on the following problem. I need to get a list of numbers out of strings but I don't know how many numbers are in each string. The strings are as follows:

my $line1 = "[HAVE 1324,2,32,324,5,643]
my $line2 = "[HAVE 4,213,5432,4]
[download]

I would ideally like to parse each line and have all the numbers of a single line in an array, say

my @numbers =();
[download]

After reading the first line, it should contain (1324,2,32,324,5,643) and after reading the second line it should contain (4,213,5432,4). Not sure how to match strings when the format isn't constant. Thanks in advance for your help, Matt.

Comment on String Matching Select or Download Code

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Re: String Matching by Anno (Deacon) on Sep 18, 2007 at 11:32 UTC
You only have to globally match each sequence of consecutive digits. A global match (in list context) returns all its matches, so this would do `my $line1 = "[HAVE 1324,2,32,324,5,643]"; my $line2 = "[HAVE 4,213,5432,4]"; for ( $line1, $line2 ) { my @numbers = /\d+/g; print "@numbers\n"; }` [download] Anno	[reply] [d/l]
Re: String Matching by bruceb3 (Pilgrim) on Sep 18, 2007 at 11:38 UTC
There are a number of ways of going about providing a solution to your problem. I have gone for a simple regex; `#!/usr/bin/env perl use strict; use warnings; use Data::Dumper; my @lines = ( "[HAVE 1324,2,32,324,5,643]", "[HAVE 4,213,5432,4]"); for my $line (@lines) { my @numbers; while ($line =~ /(\d+)/g) { push @numbers, $1; } print Dumper \@numbers; }` [download] Produces the following output; `$VAR1 = [ '1324', '2', '32', '324', '5', '643' ]; $VAR1 = [ '4', '213', '5432', '4' ];` [download] You could use s/// to remove the extra characters and use split on the commas if you like.	[reply] [d/l] [select]
Re: String Matching by mattwortho (Acolyte) on Sep 18, 2007 at 11:32 UTC
I was thinking maybe something along these lines... `if($line2 =~ /[HAVE\s(.*)]/){ my @array = split(/,/, $2); foreach my $num(@array){ print $num."\n"; } }` [download] Not sure if this is the best way....	[reply] [d/l]
Re: String Matching by ciderpunx (Vicar) on Sep 18, 2007 at 12:11 UTC
Another approach: `my @numbers = split /,/, substr($lineX,6,-1);` [download] -- Linux, perl, punk rock, cider: charlieharvey.org.uk.	[reply] [d/l]


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