NAME

Config::IOD::Reader - Read IOD/INI configuration files

VERSION

This document describes version 0.342 of Config::IOD::Reader (from Perl distribution Config-IOD-Reader), released on 2019-01-17.

SYNOPSIS

 use Config::IOD::Reader;
 my $reader = Config::IOD::Reader->new(
     # list of known attributes, with their default values
     # default_section     => 'GLOBAL',
     # enable_directive    => 1,
     # enable_encoding     => 1,
     # enable_quoting      => 1,
     # enable_backet       => 1,
     # enable_brace        => 1,
     # allow_encodings     => undef, # or ['base64','json',...]
     # disallow_encodings  => undef, # or ['base64','json',...]
     # allow_directives    => undef, # or ['include','merge',...]
     # disallow_directives => undef, # or ['include','merge',...]
     # allow_bang_only     => 1,
     # enable_expr         => 0,
     # allow_duplicate_key => 1,
     # ignore_unknown_directive => 0,
 );
 my $config_hash = $reader->read_file('config.iod');

DESCRIPTION

This module reads IOD configuration files (IOD is an INI-like format with more precise specification, some extra features, and 99% compatible with typical INI format). It is a minimalist alternative to the more fully-featured Config::IOD. It cannot write IOD files and is optimized for low startup overhead.

EXPRESSION

Expression allows you to do things like:

 [section1]
 foo=1
 bar="monkey"

 [section2]
 baz =!e 1+1
 qux =!e "grease" . val("section1.bar")
 quux=!e val("qux") . " " . val('baz')

And the result will be:

 {
     section1 => {foo=>1, bar=>"monkey"},
     section2 => {baz=>2, qux=>"greasemonkey", quux=>"greasemonkey 2"},
 }

For safety, you'll need to set enable_expr attribute to 1 first to enable this feature.

The syntax of the expression (the expr encoding) is not officially specified yet in the IOD specification. It will probably be Expr (see Language::Expr::Manual::Syntax). At the moment, this module implements a very limited subset that is compatible (lowest common denominator) with Perl syntax and uses eval() to evaluate the expression. However, only the limited subset is allowed (checked by Perl 5.10 regular expression).

The supported terms:

 number
 string (double-quoted and single-quoted)
 undef literal
 simple variable ($abc, no namespace, no array/hash sigil, no special variables)
 function call (only the 'val' function is supported)
 grouping (parenthesis)

The supported operators are:

 + - .
 * / % x
 **
 unary -, unary +, !, ~

The val() function refers to the configuration key. If the argument contains ".", it will be assumed as SECTIONNAME.KEYNAME, otherwise it will access the current section's key. Since parsing is done in a single pass, you can only refer to the already mentioned key.

Code will be compiled using Perl's eval() in the Config::IOD::Expr::_Compiled namespace, with no strict, no warnings.

ATTRIBUTES

default_section => str (default: GLOBAL)

If a key line is specified before any section line, this is the section that the key will be put in.

enable_directive => bool (default: 1)

If set to false, then directives will not be parsed. Lines such as below will be considered a regular comment:

 ;!include foo.ini

and lines such as below will be considered a syntax error (regardless of the allow_bang_only setting):

 !include foo.ini

NOTE: Turning this setting off violates IOD specification.

enable_encoding => bool (default: 1)

If set to false, then encoding notation will be ignored and key value will be parsed as verbatim. Example:

 name = !json null

With enable_encoding turned off, value will not be undef but will be string with the value of (as Perl literal) "!json null".

NOTE: Turning this setting off violates IOD specification.

enable_quoting => bool (default: 1)

If set to false, then quotes on key value will be ignored and key value will be parsed as verbatim. Example:

 name = "line 1\nline2"

With enable_quoting turned off, value will not be a two-line string, but will be a one line string with the value of (as Perl literal) "line 1\\nline2".

NOTE: Turning this setting off violates IOD specification.

enable_bracket => bool (default: 1)

If set to false, then JSON literal array will be parsed as verbatim. Example:

 name = [1,2,3]

With enable_bracket turned off, value will not be a three-element array, but will be a string with the value of (as Perl literal) "[1,2,3]".

NOTE: Turning this setting off violates IOD specification.

enable_brace => bool (default: 1)

If set to false, then JSON literal object (hash) will be parsed as verbatim. Example:

 name = {"a":1,"b":2}

With enable_brace turned off, value will not be a hash with two pairs, but will be a string with the value of (as Perl literal) '{"a":1,"b":2}'.

NOTE: Turning this setting off violates IOD specification.

enable_tilde => bool (default: 1)

If set to true (the default), then value that starts with ~ (tilde) will be assumed to use !path encoding, unless an explicit encoding has been otherwise specified.

Example:

 log_dir = ~/logs  ; ~ will be resolved to current user's home directory

With enable_tilde turned off, value will still be literally ~/logs.

NOTE: Turning this setting off violates IOD specification.

allow_encodings => array

If defined, set list of allowed encodings. Note that if disallow_encodings is also set, an encoding must also not be in that list.

Also note that, for safety reason, if you want to enable expr encoding, you'll also need to set enable_expr to 1.

disallow_encodings => array

If defined, set list of disallowed encodings. Note that if allow_encodings is also set, an encoding must also be in that list.

Also note that, for safety reason, if you want to enable expr encoding, you'll also need to set enable_expr to 1.

enable_expr => bool (default: 0)

Whether to enable expr encoding. By default this is turned on, for safety. Please see "EXPRESSION" for more details.

allow_directives => array

If defined, only directives listed here are allowed. Note that if disallow_directives is also set, a directive must also not be in that list.

disallow_directives => array

If defined, directives listed here are not allowed. Note that if allow_directives is also set, a directive must also be in that list.

allow_bang_only => bool (default: 1)

Since the mistake of specifying a directive like this:

 !foo

instead of the correct:

 ;!foo

is very common, the spec allows it. This reader, however, can be configured to be more strict.

allow_duplicate_key => bool (default: 1)

If set to 0, you can forbid duplicate key, e.g.:

 [section]
 a=1
 a=2

or:

 [section]
 a=1
 b=2
 c=3
 a=10

In traditional INI file, to specify an array you specify multiple keys. But when there is only a single key, it is unclear if the value is a single-element array or a scalar. You can use this setting to avoid this array/scalar ambiguity in config file and force user to use JSON encoding or bracket to specify array:

 [section]
 a=[1,2]

NOTE: Turning this setting off violates IOD specification.

ignore_unknown_directive => bool (default: 0)

If set to true, will not die if an unknown directive is encountered. It will simply be ignored as a regular comment.

NOTE: Turning this setting on violates IOD specification.

METHODS

new(%attrs) => obj

$reader->read_file($filename[ , $callback ]) => hash

Read IOD configuration from a file. Die on errors.

See read_string for more information on $callback argument.

$reader->read_string($str[ , $callback ]) => hash

Read IOD configuration from a string. Die on errors.

$callback is an optional coderef argument that will be called during various stages. It can be useful if you want more information (especially ordering). It will be called with hash argument %args

  • Found a directive line

    Arguments passed: event (str, has the value of 'directive'), linum (int, line number, starts from 1), line (str, raw line), directive (str, directive name), cur_section (str, current section name), args (array, directive arguments).

  • Found a comment line

    Arguments passed: event (str, 'comment'), linum, line, cur_section.

  • Found a section line

    Arguments passed: event (str, 'section'), linum, line, cur_section, section (str, section name).

  • Found a key line

    Arguments passed: event (str, 'section'), linum, line, cur_section, key (str, key name), val (any, value name, already decoded if encoded), raw_val (str, raw value).

TODO: callback when there is merging.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Config-IOD-Reader.

SOURCE

Source repository is at https://github.com/perlancar/perl-Config-IOD-Reader.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Config-IOD-Reader

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

SEE ALSO

IOD - specification

Config::IOD - round-trip parser for reading as well as writing IOD documents

IOD::Examples - sample documents

AUTHOR

perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2019, 2018, 2017, 2016, 2015, 2014 by perlancar@cpan.org.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.