Re: conf file in Perl syntax

If you are new to perl probably you don't want starting installing modules...

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};
[download]

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;
          }
    }
[download]

BE AWARE: do searches the @INC directories, so better use a path to avoid problems...

Cheers Rolf

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.

Comment on Re: conf file in Perl syntax Select or Download Code

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Re^2: conf file in Perl syntax by afoken (Chancellor) on Jun 11, 2009 at 11:23 UTC
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 /`, } [download] 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". ;-)	[reply] [d/l]
Re^2: conf file in Perl syntax by Ravendark (Acolyte) on Jun 11, 2009 at 11:25 UTC
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` [download] 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!	[reply] [d/l]
Re^3: conf file in Perl syntax by GrandFather (Saint) on Jun 11, 2009 at 21:11 UTC
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" ], );` [download] or better, a hash: `my %IPMap = ( host_1 => "192.168.1.1", host_2 => "192.168.1.2", host_3 => "192.168.1.3", );` [download] 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 $IPMapAoA;` [download] Prints: `$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' ] ];` [download] True laziness is hard work	[reply] [d/l] [select]
Re^3: conf file in Perl syntax by Anonymous Monk on Jun 11, 2009 at 12:34 UTC
$ 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	[reply]


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