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Config::Properties(3) |
User Contributed Perl Documentation |
Config::Properties(3) |
Config::Properties - Read and write property files
use Config::Properties;
# reading...
open my $fh, '<', 'my_config.props'
or die "unable to open configuration file";
my $properties = Config::Properties->new();
$properties->load($fh);
$value = $properties->getProperty($key);
# saving...
open my $fh, '>', 'my_config.props'
or die "unable to open configuration file for writing";
$properties->setProperty($key, $value);
$properties->format('%s => %s');
$properties->store($fh, $header );
Config::Properties is a near implementation of the java.util.Properties API. It
is designed to allow easy reading, writing and manipulation of Java-style
property files.
The format of a Java-style property file is that of a key-value
pair separated by either whitespace, the colon (:) character, or the equals
(=) character. Whitespace before the key and on either side of the separator
is ignored.
Lines that begin with either a hash (#) or a bang (!) are
considered comment lines and ignored.
A backslash (\) at the end of a line signifies a continuation and
the next line is counted as part of the current line (minus the backslash,
any whitespace after the backslash, the line break, and any whitespace at
the beginning of the next line).
The official references used to determine this format can be found
in the Java API docs for java.util.Properties at
<http://java.sun.com/j2se/1.5.0/docs/api/java/util/Properties.html>.
When a property file is saved it is in the format
"key=value" for each line. This can be changed by setting the
format attribute using either $object->format(
$format_string ) or
$object->setFormat(
$format_string ) (they do the same thing). The
format string is fed to printf and must contain exactly two
%s format characters. The first will be replaced
with the key of the property and the second with the value. The string can
contain no other printf control characters, but can be anything else. A
newline will be automatically added to the end of the string. The current
format string can be obtained by using
$object->format() (with no arguments) or
$object->getFormat().
If a recent version of Text::Wrap is available, long lines are
conveniently wrapped when saving.
"Config::Property" objects have this set of
methods available:
- Config::Properties->new(%opts)
- Creates a new Config::Properties object.
The optional arguments are as follows:
- file => $filename
- Opens and reads the entries from the given properties file
- format => $format
- Sets the format using for saving the properties to a file. See
"setFormat".
- wrap => 0
- Disables wrapping of long lines when saving the properties to a file.
- defaults => $defaults
- Default configuration values.
The given parameter can be a hash reference or another
Config::Properties object.
In that way several configuration objects can be chained. For
instance:
my %defaults = (...);
my $global_config = Config::Properties->new(file => '/etc/foo.properties',
defaults => \%defaults);
my $user_config = Config::Properties->new(file => '/home/jsmith/.foo/foo.properties',
defaults => $global_config);
- order => 'keep'|'alpha'|'none'
- Sets how to order the properties when saved to a file or when returned by
"properties" and
"propertyNames" methods.
"alpha" sorts the keys in
alphanumeric order. "keep" keeps the
order of the properties as added or read from a file.
"none" returns the properties
unordered.
- encoding => $encoding
- IO encoding used to read the configuration file. See PerlIO.
When "load" is called the
given encoding is used unless the file handler already has a encoding
layer applied.
"latin1" is used as the
default encoding (as specified in the Java properties
specification).
- be_like_java => 1
- When this feature is enabled, the module will try to mimic the Java
implementation as much as possible when saving files.
Currently, some escaping rules are changed and line wrapping
is disabled.
- Config::Properties->new($defaults)
- Calling "new" in this way is
deprecated.
- $p->getProperty($k, $default, $default2, ...)
- return property $k or when not defined, the first
defined "$default*".
- $p->requireProperty($k, $default, $default2, ...)
- this method is similar to "getProperty"
but dies if the requested property is not found.
- $p->setProperty($k, $v)
- set property $k value to
$v.
- $p->changeProperty($k, $v)
- $p->changeProperty($k, $v, $default, $default2, ...)
- method similar to "setPropery" but that
does nothing when the new value is equal to the one returned by
"getProperty".
An example shows why it is useful:
my $defaults=Config::Properties->new();
$defaults->setProperty(foo => 'bar');
my $p1=Config::Properties->new($defaults);
$p1->setProperty(foo => 'bar'); # we set here!
$p1->store(FILE1); foo gets saved on the file
my $p2=Config::Properties->new($defaults);
$p2->changeProperty(foo => 'bar'); # does nothing!
$p2->store(FILE2); # foo doesn't get saved on the file
- $p->deleteProperty($k)
- $p->deleteProperty($k, $recurse)
- deletes property $k from the object.
If $recurse is true, it also deletes
any $k property from the default properties
object.
- $p->properties
- returns a flatten hash with all the property key/value pairs, i.e.:
my %props=$p->properties;
- $p->getProperties
- returns a hash reference with all the properties (including those passed
as defaults).
- $p->propertyNames;
- returns the names of all the properties (including those passed as
defaults).
- $p->splitToTree()
- $p->splitToTree($regexp)
- $p->splitToTree($regexp, $start)
- builds a tree from the properties, splitting the keys with the regular
expression $re (or
"/\./" by default). For instance:
my $data = <<EOD;
name = pete
date.birth = 1958-09-12
date.death = 2004-05-11
surname = moo
surname.length = 3
EOD
open my $fh, '<', \$data;
$cfg->load();
my $tree = $cfg->splitToTree();
makes...
$tree = { date => { birth => '1958-09-12',
death => '2004-05-11' },
name => 'pete',
surname => { '' => 'moo',
length => '3' } };
The $start parameter allows to split
only a subset of the properties. For instance, with the same data as on
the previous example:
my $subtree = $cfg->splitToTree(qr/\./, 'date');
makes...
$tree = { birth => '1958-09-12',
death => '2004-05-11' };
- $p->setFromTree($tree)
- $p->setFromTree($tree, $separator)
- $p->setFromTree($tree, $separator, $start)
- This method sets properties from a tree of Perl hashes and arrays. It is
the opposite of "splitToTree".
$separator is the string used to join
the parts of the property names. The default value is a dot
(".").
$start is a string used as the
starting point for the property names.
For instance:
my $c = Config::Properties->new;
$c->setFromTree( { foo => { '' => one,
hollo => [2, 3, 4, 1] },
bar => 'doo' },
'->',
'mama')
# sets properties:
# mama->bar = doo
# mama->foo = one
# mama->foo->hollo->0 = 2
# mama->foo->hollo->1 = 3
# mama->foo->hollo->2 = 4
# mama->foo->hollo->3 = 1
- $p->changeFromTree($tree)
- $p->changeFromTree($tree, $separator)
- $p->changeFromTree($tree, $separator, $start)
- similar to "setFromTree" but internally
uses "changeProperty" instead of
"setProperty" to set the property
values.
- $p->load($file)
- loads properties from the open file $file.
Old properties on the object are discarded.
- $p->save($file)
- $p->save($file, $header)
- $p->store($file)
- $p->store($file, $header)
- save the properties to the open file $file.
Default properties are not saved.
- $p->saveToString($header)
- similar to "save", but instead of saving
to a file, it returns a string with the content.
- $p->getFormat()
- $p->setFormat($f)
- get/set the format string used when saving the object to a file.
Java docs for "java.util.Properties" at
<http://java.sun.com/j2se/1.3/docs/api/index.html>.
Config::Properties::Simple for a simpler alternative interface to
Config::Properties.
Add support for derived format as supported by Java class
org.apache.commons.configuration.PropertiesConfiguration
(<http://commons.apache.org/configuration/apidocs/org/apache/commons/configuration/PropertiesConfiguration.html>)
"Config::Properties" was originally developed
by Randy Jay Yarger. It was maintained for some time by Craig Manley and
finally it passed hands to Salvador Fandiño <sfandino@yahoo.com>,
the current maintainer.
Copyright 2001, 2002 by Randy Jay Yarger Copyright 2002, 2003 by Craig Manley.
Copyright 2003-2009, 2011-2012, 2014-2015 by Salvador Fandiño.
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
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