Config::General::Interpolated - Parse variables within Config files
use Config::General;
$conf = Config::General->new(
-ConfigFile => 'configfile',
-InterPolateVars => 1
);
This is an internal module which makes it possible to interpolate Perl style
variables in your config file (i.e. $variable or "${variable}").
Normally you don't call it directly.
Variables can be defined everywhere in the config and can be used afterwards as
the value of an option. Variables cannot be used as keys or as part of keys.
If you define a variable inside a block or a named block then it is only visible
within this block or within blocks which are defined inside this block. Well -
let's take a look to an example:
# sample config which uses variables
basedir = /opt/ora
user = t_space
sys = unix
<table intern>
instance = INTERN
owner = $user # "t_space"
logdir = $basedir/log # "/opt/ora/log"
sys = macos
<procs>
misc1 = ${sys}_${instance} # macos_INTERN
misc2 = $user # "t_space"
</procs>
</table>
This will result in the following structure:
{
'basedir' => '/opt/ora',
'user' => 't_space'
'sys' => 'unix',
'table' => {
'intern' => {
'sys' => 'macos',
'logdir' => '/opt/ora/log',
'instance' => 'INTERN',
'owner' => 't_space',
'procs' => {
'misc1' => 'macos_INTERN',
'misc2' => 't_space'
}
}
}
As you can see, the variable
sys has been defined twice. Inside the
<procs> block a variable ${sys} has been used, which then were
interpolated into the value of
sys defined inside the <table>
block, not the sys variable one level above. If sys were not defined inside
the <table> block then the "global" variable
sys would
have been used instead with the value of "unix".
Variables inside double quotes will be interpolated, but variables inside single
quotes will
not interpolated. This is the same behavior as you know of
Perl itself.
In addition you can surround variable names with curly braces to avoid
misinterpretation by the parser.
Variable names must:
- •
- start with a US-ASCII letter(a-z or A-Z) or a digit
(0-9).
- •
- contain only US-ASCII letter(a-z or A-Z), digits (0-9), the
dash (-)
colon (:), dot (.), underscore (_) and plus (+) characters.
For added clarity variable names can be surrounded by curly braces.
Config::General
Thomas Linden <tlinden |AT| cpan.org>
Autrijus Tang <[email protected]>
Wei-Hon Chen <[email protected]>
Copyright 2001 by Wei-Hon Chen <
[email protected]>. Copyright
2002-2022 by Thomas Linden <tlinden |AT| cpan.org>.
This program is free software; you can redistribute it and/or modify it under
the terms of the Artistic License 2.0.
See <
http://www.perl.com/perl/misc/Artistic.html>
2.16