CODEWITHSUNDEEP
perlrequire
Mobrine Hayde
Mobrine Hayde

Reputation: 365

perl : can't require $value from other perl file and use it in 3rd perl file

So I have 3 perl files ( 1.pl, 2.pl, 3.pl) , I want to require a value from a loop in 2.pl and print it in 3.pl

the scripts

1.pl

use strict;
use warnings;

require "./2.pl";
sub red {
    our $var;
    print "try : ";
    require "./3.pl"
}

2.pl

use strict;
use warnings;

my @array = ("http://exemple.org", "http://test.org","http://perl.org");

foreach our $var(@array){
    chomp ($var);
    red();
}

1;

3.pl

use strict;
use warnings;

our $var;

print "3 : $var\n";

1;

What I get when I open 1.pl in terminal :

try : 3 : http://exemple.org
try : try :

And what I want to get is :

try : 3 : http://exemple.org
try : 3 : http://test.org
try : 3 : http://perl.org

It seems like the 2nd require of 3.pl dont work , so what can I do?

Upvotes: 0

Views: 46

Answers (1)

simbabque
simbabque

Reputation: 54371

The require keyword stores files it has already loaded in the %INC hash.

perl -MData::Dumper -E 'say Dumper \%INC'
$VAR1 = {
    'Data/Dumper.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/x86_64-linux/Data/Dumper.pm',
    'constant.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/constant.pm',
    'feature.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/feature.pm',
    'strict.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/strict.pm',
    'warnings/register.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/warnings/register.pm',
    'Exporter.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/Exporter.pm',
    'XSLoader.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/XSLoader.pm',
    'bytes.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/bytes.pm',
    'warnings.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/warnings.pm',
    'Carp.pm' => '/home/simbabque/perl5/perlbrew/perls/perl-5.26.1/lib/5.26.1/Carp.pm'
};

When you try to require $same_filename again, it will look at $INC{$same_filename}. If that exists, it aborts.

If you want to re-run the same file you can use the do keyword instead, which just loads and executes a file. This will re-read the file from disk every time.

sub red {
    our $var;
    print "try : ";
    do "./3.pl"
}

Keep in mind that this is really bad practice. You should move this code into a function and pass lexical variables around.

Upvotes: 5

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