如何在perl中使用查找文本作为变量？

Question

I have variables in file1.pm file file1.pm

package oa;
use strict;
use warnings;
our $first1= 'DTH';
1;

Now want access this variable within variable, this is my main program but I did't get output i know problem is "oa:$var" Can i use “/oa::$var/ “ like this to access variable?

#!/usr/bin/perl
use file1;
$input='DTH';
$var=first . 1;
if($input =~ /oa::$var/){
print “DTH”;
}

Answer 1

Perl is not PHP, and the $ sigil comes in front of the package name: If you want to access a package variable, then do $PackageName::var_name .

./MyPackage.pm :

package MyPackage;  # package names should be CamelCase!
use strict;
use warnings;

our $first1 = 'DHT';
1;

./script.pl :

use strict;
use warnings;
use MyPackage;

my $input = 'DHT';
if ($input =~ /$MyPackage::first1/) {
    print "DHT\n";
}

However, you are also refering to a variable by name. This is a bad thing to do, and makes it almost impossible to understand and maintain such a program. You can use hashes instead (also known as associative arrays, maps, or dictionaries):

In MyPackage :

our %stuff = (
    first1 => 'DHT',
    other1 => 'foobar',
);

In the script:

my $var = 'first1';
if ($input =~ /$MyPackage::stuff{$var}/) {
    ...