Good, nice I like it. I read that you can have the values in an array with:

@values = $cfg->val('Section', 'Parameter'); # this will be the array 
+holding the IPs
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How can I get the names of the hosts in an array too?

you can tie to a hash, and get to iterate through the keys(variables) and values(actual values) of the hash.
an example is given in the man page of the config::inifiles itself. it is easy


 use Config::IniFiles;
  
  my %ini
  tie %ini, 'Config::IniFiles', ( -file => "/path/configfile.ini" );

  print "We have $ini{Section}{Parameter}." if $ini{Section}{Parameter
+};

my @keys = keys %{$ini{$section}}
while (($k, $v) = each %{$ini{$section}}) {...}
if( exists %{$ini{$section}}, $parameter ) {...}
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---

Vivek
-- In accordance with the prarabdha of each, the One whose function it is to ordain makes each to act. What will not happen will never happen, whatever effort one may put forth. And what will happen will not fail to happen, however much one may seek to prevent it. This is certain. The part of wisdom therefore is to stay quiet.

With your Java background you may be interested in JSON::XS which implements the JSON serialising protocol. YAML::XS may be of interested instead (YAML is a superset of JSON).

YAML is a superset of JSON

No, it isn't, at least not all YAML versions.

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

"No, it isn't" anchor link does not work; actual anchor has hyphens not underscores among "JSON", "and", "YAML": https://metacpan.org/dist/JSON-XS/view/XS.pm#JSON-and-YAML.

while (my ($host,$ip) = each(%$config)) {
    print "$host => $ip\n";
}
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cheers si_lence

There is a poor man's solution for evaluating configfiles as scripts with do

this works with your example:

our $config;
do './conf.pl' or die "Can't read config $!";
print $config->{host_1};
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or even more error proved described in the docs with

# read in config files: system first, then user
for $file ("/share/prog/defaults.rc",
           "$ENV{HOME}/.someprogrc")
    {
          unless ($return = do $file) {
              warn "couldn't parse $file: $@" if $@;
              warn "couldn't do $file: $!"    unless defined $return;
              warn "couldn't run $file"       unless $return;
          }
    }
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BE AWARE: do searches the @INC directories, so better use a path to avoid problems...

UPDATE: As I wrote the config-file is evaluated as script not parsed as data, so be aware of necessities of securing this code! If it's just a one way script, and you have full control it's ok. If you mean to write a full scale program for others, better use a config-module.

Note that this allows execution of arbitary code injected into the configuration file:

$config = {
    host_1 => '192.168.1.1', 
    host_2 => '192.168.1.2', 
    host_3 => '192.168.1.3', 
    host_4 => '192.168.1.4',
    you_will_have_a_really_bad_day => `rm -rf /`,
}
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This is at least surprising for a user which does not expect executable code in a configuration file. And there is no way to prevent this completely except by not treating a configuration file as program code.

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

Thanks LanX for your reply. I am new guy in perl, but I installed the IniFiles module. what you are writing is hard-to-read syntax for me. What I need is a little code snippet that does the following: I have the inifile:

[hosts]
# hostname = IP
host_1 = 192.168.1.1
host_2 = 192.168.1.2
host_3 = 192.168.1.3
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The only thing I need is a little piece of code that will get all the hostnames into an array @hostnames and all the IPs into an array @ips. Is this possible? Thank you!

Don't do that (parallel arrays). Either use an array of arrays (AoA):

my @IPMap = (
    [ "host_1", "192.168.1.1" ],
    [ "host_2", "192.168.1.2" ],
    [ "host_3", "192.168.1.3" ],
);
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or better, a hash:

my %IPMap = (
    host_1 => "192.168.1.1",
    host_2 => "192.168.1.2",
    host_3 => "192.168.1.3",
);
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YAML allows both structures to be generated directly from the configuration file. For example:

use strict;
use warnings;
use Data::Dump::Streamer;
use YAML ();

my $yamlStr = <<END_YAML;
---
host_1: "192.168.1.1"
host_2: "192.168.1.2"
host_3: "192.168.1.3"
---
-
    - host_1
    - "192.168.1.1"
-
    - host_2
    - "192.168.1.2"
-
    - host_3
    - "192.168.1.3"
END_YAML

my ($IPMapH, $IPMapAoA) = YAML::Load ($yamlStr);

Dump $IPMapH;
Dump $IPMapAoA;
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Prints:

$HASH1 = {
           host_1 => '192.168.1.1',
           host_2 => '192.168.1.2',
           host_3 => '192.168.1.3'
         };
$ARRAY1 = [
            [
              'host_1',
              '192.168.1.1'
            ],
            [
              'host_2',
              '192.168.1.2'
            ],
            [
              'host_3',
              '192.168.1.3'
            ]
          ];
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---

True laziness is hard work

$ cat hosts.conf
<Hosts>
host_1 = 192.168.1.1
host_2 = 192.168.1.2
host_3 = 192.168.1.3
</Hosts>

$ cat hosts.pl

#!/usr/local/bin/perl -w
use Config::General(ParseConfig);
$configFile='hosts.conf';
my %config = ParseConfig($configFile);
foreach my $host (keys(%{$config{Hosts}}))
{
print "Machine : $host => $config{Hosts}{$host}\n";
}

$ ./hosts.pl
Machine : host_1 => 192.168.1.1
Machine : host_2 => 192.168.1.2
Machine : host_3 => 192.168.1.3

#!/usr/bin/perl

use strict;

my $config = {
    host_1 => '192.168.1.1',
    host_2 => '192.168.1.2',
    host_3 => '192.168.1.3',
    host_4 => '192.168.1.4'
};

for my $i ( keys %{$config} ) {
    print "key: $i --- value: $config->{$i}\n";
}
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