This is Perl, you can do anything. So desing whatever syntax will be most comfortable to your users. I usualy use %variablename% in config files and templates and so far it worked fine with my users. (As you can guess by now they are all Windows users.)

If you happen to use Config::IniHash you can specify a function to be called for each option read and perform whatever transformations you like. Eg. if you wanted the users to use %foo% if they want to include the "foo" option in the current section and %[sec]foo% to include the "foo" option in the "sec" section. you could do it like this:

use Config::IniHash qw(ReadINI);

$config = ReadINI('c:\temp\zkINI.ini', systemvars => 0,
    forValue => sub {
        my ($name, $value, $sectionname, $INIhashref) = @_;
        $value =~ s{%(?:\[([^\]%]+)\])?([^%]*)%}{
            if ($2 eq '') {
                '%'
            } elsif ($1 eq '') {
                $INIhashref->{$sectionname}{$2}
            } else {
                $INIhashref->{$1}{$2}
            }
        }ge;
        return $value;
    }
);

use Data::Dumper;

print Dumper($config);
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Hi Jenda,

Thanks for the response. That is exactly what I was looking for.

I have been trying to go over your code (excellent code by the way) and the hash part is hard for me to understand.

Could you please explain me how I can obtain the different values from the hash?

Thanks.

The thing returned by ReadINI() is a reference to a hash of hashes. This means that:

• to access a specific value in a specific section: $config->{sectionName}{valueName}
• to list the sections: foreach my $sectionName (keys %$config) {...
• to list the values in a section:
  foreach my $name (%{$config->{sectionName}}) { print "$name = $config->{sectionName}{$name}\n"; }
  or
  for my $Section ($config->{sectionName) { foreach my $name (%$Section) { print "$name = $Section->{$name}\n"; }} or ...
I think you should read the perlreftut and perldsc manpages.

Jenda


We'd like to help you learn to help yourself Look around you, all you see are sympathetic eyes Stroll around the grounds until you feel at home    -- P. Simon in Mrs. Robinson

Config::Tiny in particular looks like a Windows .ini file --

    [section-name]
    var1=value1
    var2=value2

    [another section]
    var3=value3
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yeah I am using this config style:

But if I have :

[section]
var1=value1
var2=value1/value2


[another section]
var3=value1/value3
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Since value1 is repeated so many times, how would you suggest I write the config file?

So since:
var1 = value1 and
var2 = value1/value2

Should I make
var2 = var1 . '/value2' or
var2 = var1 + /value2

Hope I was clear...please let me know if you didn't understand.

Thanks.

# Use the appropriate syntax for your module:
my $root    = ...
my $code    = ...
my $include = ...
my $lib     = ...

foreach ($code, $include, $lib) {
   s/%ROOT%/$root/gi;
   
   # -or-
   #
   # $code =~ s/%([A-Z][A-Z_]*)%/
   #    if ($1 eq 'ROOT') {
   #       $root
   #    } elsif (exists($ENV{$1})) {
   #       $ENV{$1}
   #    } else {
   #       $1
   #    }
   # /eg
}
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Basically I want to create a config file where the variables can be changed by people who don't know perl.

So I was wondering...what is the best way to create the config file in terms of substituting variables that will be used over and over again in the config file.

I just gave the example of the $root . '\code' , but is there a better way to subsititute the root variable in the config file?

Thanks.

If you're so concerned about the complexity the config file, why don't you write an interactive configuration utility?

Back to the matter immedately at hand...

You keep talking about the config file, while you should be talking about the module that reads the config file and the program that uses the module. If you used the code I posted earlier in this thread, you could write your config file as:

[path]
root    = C:\test
code    = %root%\code1
include = %root%\include
lib     = %root%\lib
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instead of

[path]
root    = C:\test
code    = C:\test\code1
include = C:\test\include
lib     = C:\test\lib
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It doesn't get any simpler (from the config file's perspective). What else do you want?

# cat test.ini
[path]
root = C:\test
code = $root . '\code1'

# cat test.pl
use Config::IniFiles;
$ini = Config::IniFiles->new(-file => 'test.ini');
$root = $ini->val('path', 'root');
print "root = $root\n";
$code = $ini->val('path', 'code');
print "code = $code\n";
$code = eval $code;
print "code = $code\n";

# perl test.pl
root = C:\test
code = $root . '\code1'
code = C:\test\code1
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I don't think it's wise to give the users so much power. Not only would eval"" let them run whatever code they want inside the application (which may or may not matter much) but it can also easily break the app in ways that will not be aparent to the user.

Besides you will want them to be able to reuse whatever option they like, not just the "root". So they would either have to use

 [path]
 root = C:\test
 code = $ini->val('path', 'root') . '\code1'
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or something similar or you'd have to copy all the values into whatever package the eval""ed code runs in. Which is again not something you want to do.

It's (IMnsHO) better to invent a special, more restricted syntax and parse it instead of eval""ing.

Jenda


We'd like to help you learn to help yourself Look around you, all you see are sympathetic eyes Stroll around the grounds until you feel at home    -- P. Simon in Mrs. Robinson

Hi,

Thanks for the reply. Is there an easier way to use substitutions like I have used above. Something easy that people who don't know perl ( that is don't know what '$' or '.' is, can update, append or change the config file)

Since I am repeating a lot of path names, I wanted to substitute those variables throughout the config file, so inorder to change all of them, only one change would be required.

Thank you.