Config::Record.3pm

Langue: en

Autres versions - même langue

Version: 2007-12-12 (fedora - 01/12/10)

Section: 3 (Bibliothèques de fonctions)

NAME

Config::Record - Configuration file access

SYNOPSIS

   use Config::Record;
 
 
   # Create an empty record & then load from file
   my $config = Config::Record->new();
   $config->load("/etc/myapp.cfg");
 
   # Create & load, then save to filename
   my $config = Config::Record->new(file => "/etc/myapp.cfg");  
   $config->save("/etc/myapp.cfg");
 
   # Load / save from filehandle
   my $fh = IO::File->new("/etc/myapp.cfg");
   my $config = Config::Record->new(file => $fh);
   $config->save($fh);
 
   # Get a config value, throw error if not found
   my $value = $config->get("foo");
 
   # Get a config value, return 'eek' if not found
   my $value = $config->get("foo", "eek");
 
   # Set a value
   $config->set("foobar", "wizz");
 
   # Get a deep config value (ie nested hash)
   my $value = $config->get("foo/bar", "eek");
 
   # Get first element of an array param
   my $value = $config->get("people/[0]/forename");
 
   # Get the raw hash reference forming the record
   my $record = $config->record();
 
   # Get a new config object rooted at a sub-hash
   my $config = $config->view("foo");
 
 

DESCRIPTION

This module provides an API for loading and saving of simple configuration file records. Entries in the configuration file are essentially key,value pairs, with the key and values separated by a single equals symbol. The "key" consists only of alphanumeric characters. There are three types of values, scalar values can contain anything except newlines. Trailing whitespace will be trimmed unless the value is surrounded in double quotes. eg
   foo = Wizz
   foo = "Wizz....    "
 
 

Long lines can be split with a backslash character, without introducing newlines. Without double quotes, whitespace at beginning and end of lines will be trimmed eg

   foo = This is a long \
         line of text
   foo = "This is a long " \
         "line of text"
 
 

Multi-line strings can be provided as 'HERE' documents, eg

   foo = <<EOF
 This is a multiple paragraph
 block of text with newlines
 preserved
 EOF
 
 

Array values consist of a single right round bracket, following by one "value" per line, terminated by a single left round bracket. eg

   foo = (
     Wizz
     "Wizz...    "
   )
 
 

Hash values consist of a single right curly bracket, followed by one key,value pair per line, terminated by a single left curly bracket. eg

   foo = {
     one = Wizz
     two = "Wizz....  "
   }
 
 

Arrays and hashes can be nested to arbitrary depth.

EXAMPLE

   name = Foo
   title = "Wizz bang wallop"
   eek = (
     OOhh
     Aahhh
     Wizz
   )
   people = (
     {
       forename = John
       surnamne = Doe
     }
     {
       forename = Some
       surname = One
     }
   )
   wizz = {
     foo = "Elk"
     ooh = "fds"
   }
 
 

EXTRA PARSER FEATURES

The syntax described thus far is classed as the base feature set. By passing the "features" parameter when creating an instance of the "Config::Record" class, it is posible to turn on certain extra features

QUOTED NON-ALPHANUMERIC KEYS

The keys for configuration parameters are normally restricted to only contain the characters 'a-Z', '0-9', '_', '-' and '.'. Sometimes it is desirable to allow arbitrary characters for keys. If this capability is required then the "quotedkeys" parameter can be set.

EXAMPLE

   name = Foo
   title = "Wizz bang wallop"
   " some parameter " = (
      foo
      bar
   }
   "an embeded \" quote" = bar
   "an embeded \\ backslash" = wizz
 
 

EXTERNAL INCLUDE FILES

With large configuration files it can be desirable to split them into a number of smaller files. If this capability is required, then the "includes" feature can be requested. Each included file must follow the syntax rules already described.

EXAMPLE

In the main file

   name = Foo
   title = "Wizz bang wallop"
   foo = @include(somefile.cfg)
 
 

And in somefile.cfg

   firstname = Joe
   lastname = Blogs
 
 

Is equivalent to

   name = Foo
   title = "Wizz bang wallop"
   foo = {
     firstname = Joe
     lastname = Blogs
   }
 
 

METHODS

my $config = Config::Record->new([file => $file], [features => \%features]);
Creates a new config object, loading parameters from the file specified by the "file" parameter. The "file" parameter can either be a string representing a fully qualified filename, or a IO::Handle object. If the "file" parameter is a string, this filename will be saved and future calls to "load" or "save" are permitted to omit the filename. If the "file" parameter is not supplied then an empty configuration record is created.

The "features" parameter allows extra parser features to be enabled. The two valid keys for the associated hash as "includes" and "quotedkeys" as described earlier in this document.

$config->load([$file]);
Loads and parses a configuration record. The "file" parameter can either be a string representing a fully qualified filename, or an IO::Handle object. The $file parameter may be omitted, if a filename was specified in the constructor, or in previous calls to "load" or "save". Prior to loading the record, the current contents of this configuration are cleared.
$config->save([$file]);
Saves the configuration record to a file. The "file" parameter can either be a string representing a fully qualified filename, or an IO::Handle object opened for writing. The $file parameter may be omitted, if a filename was specified in the constructor, or in previous calls to "load" or "save".
my $value = $config->get($key[, $default]);
Gets the value of a configuration parameter corresponding to the name "key". If there is no value in the record, then the optional "default" is returned.
$config->set($key, $value);
Sets the value of a configuration parameter corresponding to the name "key".
$config->view($key)
Return a new Config::Record object, rooted at the specified key. If the key doesn't resolve to a hash reference an error will be raised.
my $record = $config->record();
Retrieves a hash reference for the entire configuration record. Currently this is the actual internal storage record, so changes will modify the configuration. In the next release this will be changed to be a deep clone of the internal storage record.

BUGS

Config::Record has the following limitations
*
If you load and then save a configuration file all comments are removed & whitespace normalized.
*
Ordering of elements in hash ref are not preserved across load and save sequence

These limitations may be fixed in a future release if there is demand from users...

AUTHORS

Daniel Berrange <dan@berrange.com> Copyright (C) 2000-2007 Daniel P. Berrange <dan@berrange.com>

SEE ALSO

perl(1)