[SOLVED] perl improve regex query

kdelover · 02-22-2011, 08:10 AM

hi,

I want to get rid of the repetitive \s+(\d+) in my pattern.can any one suggest a better way of doing this.Thanks.

Code:

#!/usr/bin/perl
use strict;
use warnings;
my $mem=`cat /proc/meminfo`;
my @arr=$mem=~m/MemTotal:\s+(\d+).*MemFree:\s+(\d+).*SwapTotal:\s+(\d+).*SwapFree:\s+(\d+)/s;
map { print $_."\n" } @arr;

To get all the digits i can do this m/.*:\s+(\d+).*/g

Tinkster · 02-22-2011, 10:28 AM

Code:

my @arr=$mem=~m/(?:MemTotal|MemFree|SwapTotal|SwapFree):\s+(\d+)/gxs;

Cheers,
Tink

kdelover · 02-22-2011, 12:17 PM

Thanks its works! i had to dig a bit to see what exactly you were doing as i am new to perl & regex

i wanted to clear few things,the reason for using ?: is not to save the matched pattern in the memory?So,if you dont use ?: i guess $1 should contain MemTotal,MemFree,SwapTotal,SwapFree. Is that right?

i still find it little tricky how the patterning matching options are xs working,although i understand how g works in the above the example.

Thanks again !!

Tinkster · 02-22-2011, 01:46 PM

Quote:

Originally Posted by kdelover

Thanks its works! i had to dig a bit to see what exactly you were doing as i am new to perl & regex

i wanted to clear few things,the reason for using ?: is not to save the matched pattern in the memory?So,if you dont use ?: i guess $1 should contain MemTotal,MemFree,SwapTotal,SwapFree. Is that right?

Yup. Correctly assessed.

Quote:

Originally Posted by kdelover

i still find it little tricky how the patterning matching options are xs working,although i understand how g works in the above the example.

Thanks again !!

Heh. I'm sure you'll get the hang of it really soon. For some
in-depth coverage have a look at "Mastering regular expressions" in
your local library (or add it to your personal library) ... awesome
book, w/ a strong focus on RegEx & perl (while it also covers aspects
of RE's in other languages and a variety of regex engines).

Cheers,
Tink

kdelover · 02-23-2011, 12:14 AM

Cool.using only g works too.thanks