CODEWITHSUNDEEP
perlif-statement
yoko
yoko

Reputation: 511

if query to compare two lists in perl

I have 2 lists, one is a list of files and the other is a logfile.

I want the if query to print out every line of the logfile where a file from the list is named. E.g.: list of files:

myfile1.txt
myfile2.txt

logfile:

line 1   html
line 2   filename="myfile2.txt"
line 3   /html
line 4   /xml

The desired output would be :

myfile2.txt found at line 2

I've tried several queries, such as

if(index($Lines_Logfile[$logcounter] ,'Lines_Name[$namecounter]') != -1);

or

if($Lines_Logfile[$logcounter] =~ m/$Lines_Name[$namecounter]/);

where $Lines_Logfile and $Lines_Name are the lists, and $namecounter and $logcounter are the lines of the for loops.

Upvotes: 0

Views: 78

Answers (1)

Miller
Miller

Reputation: 35208

You can use a regular expression. The trick is recognizing that you need to use quotemeta or \Q...\E to escape regex special characters, and word boundaries \b to prevent matching a substring.

use strict;
use warnings;
use autodie;

my @files = qw(myfile1.txt myfile2.txt);

#open my $fh, '<', 'yourfile.log';   
my $fh = \*DATA;   # Testing data used for debug purposes

while (<$fh>) {
    for my $file (@files) {
        if (/\b\Q$file\E\b/) {
            print "$file found at line $.: $_";
        }
    }
}

__DATA__
html
filename="myfile2.txt"
/html
/xml

Outputs:

myfile2.txt found at line 2: filename="myfile2.txt"

Upvotes: 3

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