1Config::Properties(3) User Contributed Perl DocumentationConfig::Properties(3)
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6 Config::Properties - Read and write property files
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9 use Config::Properties;
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11 # reading...
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13 open my $fh, '<', 'my_config.props'
14 or die "unable to open configuration file";
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16 my $properties = Config::Properties->new();
17 $properties->load($fh);
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19 $value = $properties->getProperty($key);
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21
22 # saving...
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24 open my $fh, '>', 'my_config.props'
25 or die "unable to open configuration file for writing";
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27 $properties->setProperty($key, $value);
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29 $properties->format('%s => %s');
30 $properties->store($fh, $header );
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33 Config::Properties is a near implementation of the java.util.Properties
34 API. It is designed to allow easy reading, writing and manipulation of
35 Java-style property files.
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37 The format of a Java-style property file is that of a key-value pair
38 separated by either whitespace, the colon (:) character, or the equals
39 (=) character. Whitespace before the key and on either side of the
40 separator is ignored.
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42 Lines that begin with either a hash (#) or a bang (!) are considered
43 comment lines and ignored.
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45 A backslash (\) at the end of a line signifies a continuation and the
46 next line is counted as part of the current line (minus the backslash,
47 any whitespace after the backslash, the line break, and any whitespace
48 at the beginning of the next line).
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50 The official references used to determine this format can be found in
51 the Java API docs for java.util.Properties at
52 <http://java.sun.com/j2se/1.5.0/docs/api/java/util/Properties.html>.
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54 When a property file is saved it is in the format "key=value" for each
55 line. This can be changed by setting the format attribute using either
56 $object->format( $format_string ) or $object->setFormat( $format_string
57 ) (they do the same thing). The format string is fed to printf and must
58 contain exactly two %s format characters. The first will be replaced
59 with the key of the property and the second with the value. The string
60 can contain no other printf control characters, but can be anything
61 else. A newline will be automatically added to the end of the string.
62 The current format string can be obtained by using $object->format()
63 (with no arguments) or $object->getFormat().
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65 If a recent version of Text::Wrap is available, long lines are
66 conveniently wrapped when saving.
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69 "Config::Property" objects have this set of methods available:
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71 Config::Properties->new(%opts)
72 Creates a new Config::Properties object.
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74 The optional arguments are as follows:
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76 file => $filename
77 Opens and reads the entries from the given properties file
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79 format => $format
80 Sets the format using for saving the properties to a file. See
81 "setFormat".
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83 wrap => 0
84 Disables wrapping of long lines when saving the properties to a
85 file.
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87 defaults => $defaults
88 Default configuration values.
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90 The given parameter can be a hash reference or another
91 Config::Properties object.
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93 In that way several configuration objects can be chained. For
94 instance:
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96 my %defaults = (...);
97 my $global_config = Config::Properties->new(file => '/etc/foo.properties',
98 defaults => \%defaults);
99 my $user_config = Config::Properties->new(file => '/home/jsmith/.foo/foo.properties',
100 defaults => $global_config);
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102 order => 'keep'|'alpha'|'none'
103 Sets how to order the properties when saved to a file or when
104 returned by "properties" and "propertyNames" methods.
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106 "alpha" sorts the keys in alphanumeric order. "keep" keeps the
107 order of the properties as added or read from a file. "none"
108 returns the properties unordered.
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110 encoding => $encoding
111 IO encoding used to read the configuration file. See PerlIO.
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113 When "load" is called the given encoding is used unless the
114 file handler already has a encoding layer applied.
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116 "latin1" is used as the default encoding (as specified in the
117 Java properties specification).
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119 be_like_java => 1
120 When this feature is enabled, the module will try to mimic the
121 Java implementation as much as possible when saving files.
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123 Currently, some escaping rules are changed and line wrapping is
124 disabled.
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126 Config::Properties->new($defaults)
127 Calling "new" in this way is deprecated.
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129 $p->getProperty($k, $default, $default2, ...)
130 return property $k or when not defined, the first defined
131 "$default*".
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133 $p->requireProperty($k, $default, $default2, ...)
134 this method is similar to "getProperty" but dies if the requested
135 property is not found.
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137 $p->setProperty($k, $v)
138 set property $k value to $v.
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140 $p->changeProperty($k, $v)
141 $p->changeProperty($k, $v, $default, $default2, ...)
142 method similar to "setPropery" but that does nothing when the new
143 value is equal to the one returned by "getProperty".
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145 An example shows why it is useful:
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147 my $defaults=Config::Properties->new();
148 $defaults->setProperty(foo => 'bar');
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150 my $p1=Config::Properties->new($defaults);
151 $p1->setProperty(foo => 'bar'); # we set here!
152 $p1->store(FILE1); foo gets saved on the file
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154 my $p2=Config::Properties->new($defaults);
155 $p2->changeProperty(foo => 'bar'); # does nothing!
156 $p2->store(FILE2); # foo doesn't get saved on the file
157
158 $p->deleteProperty($k)
159 $p->deleteProperty($k, $recurse)
160 deletes property $k from the object.
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162 If $recurse is true, it also deletes any $k property from the
163 default properties object.
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165 $p->properties
166 returns a flatten hash with all the property key/value pairs, i.e.:
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168 my %props=$p->properties;
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170 $p->getProperties
171 returns a hash reference with all the properties (including those
172 passed as defaults).
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174 $p->propertyNames;
175 returns the names of all the properties (including those passed as
176 defaults).
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178 $p->splitToTree()
179 $p->splitToTree($regexp)
180 $p->splitToTree($regexp, $start)
181 builds a tree from the properties, splitting the keys with the
182 regular expression $re (or "/\./" by default). For instance:
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184 my $data = <<EOD;
185 name = pete
186 date.birth = 1958-09-12
187 date.death = 2004-05-11
188 surname = moo
189 surname.length = 3
190 EOD
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192 open my $fh, '<', \$data;
193 $cfg->load();
194 my $tree = $cfg->splitToTree();
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196 makes...
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198 $tree = { date => { birth => '1958-09-12',
199 death => '2004-05-11' },
200 name => 'pete',
201 surname => { '' => 'moo',
202 length => '3' } };
203
204 The $start parameter allows to split only a subset of the
205 properties. For instance, with the same data as on the previous
206 example:
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208 my $subtree = $cfg->splitToTree(qr/\./, 'date');
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210 makes...
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212 $tree = { birth => '1958-09-12',
213 death => '2004-05-11' };
214
215 $p->setFromTree($tree)
216 $p->setFromTree($tree, $separator)
217 $p->setFromTree($tree, $separator, $start)
218 This method sets properties from a tree of Perl hashes and arrays.
219 It is the opposite of "splitToTree".
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221 $separator is the string used to join the parts of the property
222 names. The default value is a dot (".").
223
224 $start is a string used as the starting point for the property
225 names.
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227 For instance:
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229 my $c = Config::Properties->new;
230 $c->setFromTree( { foo => { '' => one,
231 hollo => [2, 3, 4, 1] },
232 bar => 'doo' },
233 '->',
234 'mama')
235
236 # sets properties:
237 # mama->bar = doo
238 # mama->foo = one
239 # mama->foo->hollo->0 = 2
240 # mama->foo->hollo->1 = 3
241 # mama->foo->hollo->2 = 4
242 # mama->foo->hollo->3 = 1
243
244 $p->changeFromTree($tree)
245 $p->changeFromTree($tree, $separator)
246 $p->changeFromTree($tree, $separator, $start)
247 similar to "setFromTree" but internally uses "changeProperty"
248 instead of "setProperty" to set the property values.
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250 $p->load($file)
251 loads properties from the open file $file.
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253 Old properties on the object are discarded.
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255 $p->save($file)
256 $p->save($file, $header)
257 $p->store($file)
258 $p->store($file, $header)
259 save the properties to the open file $file. Default properties are
260 not saved.
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262 $p->saveToString($header)
263 similar to "save", but instead of saving to a file, it returns a
264 string with the content.
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266 $p->getFormat()
267 $p->setFormat($f)
268 get/set the format string used when saving the object to a file.
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271 Java docs for "java.util.Properties" at
272 <http://java.sun.com/j2se/1.3/docs/api/index.html>.
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274 Config::Properties::Simple for a simpler alternative interface to
275 Config::Properties.
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278 Add support for derived format as supported by Java class
279 org.apache.commons.configuration.PropertiesConfiguration
280 (<http://commons.apache.org/configuration/apidocs/org/apache/commons/configuration/PropertiesConfiguration.html>)
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283 "Config::Properties" was originally developed by Randy Jay Yarger. It
284 was maintained for some time by Craig Manley and finally it passed
285 hands to Salvador Fandiño <sfandino@yahoo.com>, the current maintainer.
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288 Copyright 2001, 2002 by Randy Jay Yarger Copyright 2002, 2003 by Craig
289 Manley. Copyright 2003-2009, 2011-2012, 2014-2015 by Salvador Fandiño.
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291 This library is free software; you can redistribute it and/or modify it
292 under the same terms as Perl itself.
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296perl v5.36.0 2023-01-20 Config::Properties(3)