You haven't said what's variable and what's fixed so there are any number of possible solutions. If you want to remove the 99%, you can just say $string =~ s/99%//; or if you want to remove all things that look like percentages, you could say $string =~ s/\d+%//g;. But you may want something more complicated. I don't know.

"I want to extract everything contained within the first pair of parentheses in the given string"

In that case....

#!/usr/bin/perl -w
use strict;

my $string = "Identities = 1529/1540 (99%), Gaps = 2/1540 (0%)";
my ($wanted) = $string =~ m#\((.*?)\)#;
print "$wanted\n";

Re^2: Regular expression question

rangersfan

created: 2006-03-31 02:40:36

perlmonks

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prlmnks

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what does the m# do? m is for match, but I don't understand what the # does.

Re^3: Regular expression question

gube

created: 2006-03-31 02:50:40

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prlmnks

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Hi rangersfan,

(/) This is the usual delimiter for the text part of a regular expression. you can also use (#) as delimiter. By using usual delimiter with regexp i have given the code below you can also refer that for your understand :-p

Re^4: Regular expression question

rangersfan

created: 2006-03-31 02:52:17

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prlmnks

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learn something new everyday.... thanks!

Re^5: Regular expression question

johngg

created: 2006-03-31 03:59:10

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You can choose other symbols, eg the pipe symbol '|' or you can choose bracket pairs eg m{^abc}. Note that the slash '/' is the default character and using this allows you to omit the 'm' operator, eg /^abc/. The usual reason to choosing something other than the '/' is when matching on *nix paths so that you don't have to keep escaping the '/'s, eg /\/path\/to\/file/ versus m#/path/to/file#.

You can also choose different delimiters for doing substitution, eg s|/path/to/|| or s{abc}{xyz}. Note when using paired brackets you need a set around both the "to be replaced" and the "replace with" strings.

Cheers,

JohnGG

Hi try this,

#!/usr/local/bin/perl -w
use strict;
my $str = "Identities = 1529/1540 (99%), Gaps = 2/1540 (0%)";
my ($output) = $str =~ m/(\d+%)/gsi;
print "$output\n";

use strict;
use warnings;

my ($text, %percent);

$text = 'Identities = 1529/1540 (99%), Gaps = 2/1540 (0%)';
$percent{$1} = $2 while $text =~ /(\w+) = \d+\/\d+ \((\d+)%\)/g;

for (sort keys %percent) {
    print "$_ : $percent{$_}\n";
}