CODEWITHSUNDEEP
regexperlparsing
user1824906
user1824906

Reputation: 59

parse only needed line from file

How to parse only a line which has a word QUERY? I tried:

my @strs  = loadf('ck.txt');    

while(1)
{
    my $str = shift @strs;
    if(!$str)   
    {
        exit;
    }
    if($str =~ /QUERY/)
    {
        ($cl) = $str =~ /QUERY: (.*?)/;
        open F, ">>go.txt";
        print F $cl;
        close F;    
    }
}




sub loadf {
    open (F, "<".$_[0]) or erroropen($_[0]);
    chomp(my @data = <F>);
    close F;
    return @data;
}

ck.txt:

22.11.2012 16:55:45 +02:00
IP: 99.992.92.992
QUERY: BANNER_LANG=ru; textext community-lang=ru
REFERER: http:/site.ru/827
AGENT: Opera/9.80 (Windows NT 6.0) Presto/2.12.388 Version/12.10

22.11.2012 16:55:44 +02:00
IP: 89.189.191.6
QUERY: BANNER_LANG=ru; text; community-lang=ru
REFERER: http:/site.ru/444
AGENT: Opera/9.80 (Windows NT 5.1; U; ru) Presto/2.10.289 Version/12.00

But it doesn't work=\­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

Upvotes: 1

Views: 89

Answers (3)

TLP
TLP

Reputation: 67900

You are complicating things. Your problem can be solved with a one-liner:

perl -nlwe 'print if /^QUERY/' query.txt >> go.txt

You may consider removing the start of line anchor ^ from the regex if your data is irregular.

If you wish to remove the word QUERY: you can use this one-liner:

perl -nlwe 'print if s/^QUERY:\s*//' query.txt >> go.txt

The deparsed code for this one-liner is (edited for simplicity):

use warnings;                       # -w option: enable warnings
BEGIN { $/ = "\n"; $\ = "\n"; }     # -l option: handle line endings
while (<>) {                        # -n option: read input file or stdin
    chomp;                          # -l option again
    print $_ if s/^QUERY:\s+//;     # our code
}

Upvotes: 0

dan1111
dan1111

Reputation: 6566

Your problem was the (.*?). ? makes the match non-greedy, so it will match as few characters as possible while still satisfying the regex. In this case, that was always zero characters.

Also, your code can be simplified:

use strict;
use warnings;

my @strs  = ('BLAH', ' QUERY: foobarbaz', 'QUERY asdf');    

#open the file once: more efficient.
open my $file, '>>', 'go.txt' or die "Can't open file: $!";
for  my $str (@strs)
{
    #Perform all matching logic in one go.
    if($str =~ m/QUERY: (.*)/)
    {
        print {$file} $1;
    }
}
close $file;

Upvotes: 1

garyh
garyh

Reputation: 2852

Either remove the ? to make it greedy or add $ after the closing )

Eg

QUERY: (.*)

or

QUERY: (.*?)$

Upvotes: 0

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