1CGI::Ex::Conf(3) User Contributed Perl Documentation CGI::Ex::Conf(3)
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6 CGI::Ex::Conf - Conf Reader/Writer for many different data format types
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9 version 2.50
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12 use CGI::Ex::Conf qw(conf_read conf_write);
13 my $hash = conf_read("/tmp/foo.yaml");
15 conf_write("/tmp/foo.yaml", {key1 => $val1, key2 => $val2});
17 ### OOP interface
20 my $cob = CGI::Ex::Conf->new;
22 my $full_path_to_file = "/tmp/foo.val"; # supports ini, sto, val, pl, xml
24 my $hash = $cob->read($file);
25 local $cob->{default_ext} = 'conf'; # default anyway
27 my @paths = qw(/tmp, /home/pauls);
30 local $cob->{paths} = \@paths;
31 my $hash = $cob->read('My::NameSpace');
32 # will look in /tmp/My/NameSpace.conf and /home/pauls/My/NameSpace.conf
33 my $hash = $cob->read('My::NameSpace', {paths => ['/tmp']});
36 # will look in /tmp/My/NameSpace.conf
37 local $cob->{directive} = 'MERGE';
40 my $hash = $cob->read('FooSpace');
41 # OR #
42 my $hash = $cob->read('FooSpace', {directive => 'MERGE'});
43 # will return merged hashes from /tmp/FooSpace.conf and /home/pauls/FooSpace.conf
44 # immutable keys are preserved from originating files
45 local $cob->{directive} = 'FIRST';
48 my $hash = $cob->read('FooSpace');
49 # will return values from first found file in the path.
50 local $cob->{directive} = 'LAST'; # default behavior
53 my $hash = $cob->read('FooSpace');
54 # will return values from last found file in the path.
55 ### manipulate $hash
58 $cob->write('FooSpace'); # will write it out the changes
59
61 There are half a million Conf readers out there. Why not add one more.
62 Actually, this module provides a wrapper around the many file formats
63 and the config modules that can handle them. It does not introduce any
64 formats of its own.
65 This module also provides a preload ability which is useful in
67 conjunction with mod_perl.
68 Oh - and it writes too.
70
72 "read_ref"
73 Takes a file and optional argument hashref. Figures out the type
74 of handler to use to read the file, reads it and returns the ref.
75 If you don't need the extended merge functionality, or key
76 fallback, or immutable keys, or path lookup ability - then use this
77 method. Otherwise - use ->read.
78 "read"
80 First argument may be either a perl data structure, yaml string, a
81 full filename, or a file "namespace".
82 The second argument can be a hashref of override values (referred
84 to as $args below)..
85 If the first argument is a perl data structure, it will be copied
87 one level deep and returned (nested structures will contain the
88 same references). A yaml string will be parsed and returned. A
89 full filename will be read using the appropriate handler and
90 returned (a file beginning with a / or ./ or ../ is considered to
91 be a full filename). A file "namespace" (ie "footer" or
92 "my::config" or "what/ever") will be turned into a filename by
93 looking for that namespace in the paths found either in
94 $args->{paths} or in $self->{paths} or in @DEFAULT_PATHS.
95 @DEFAULT_PATHS is empty by default as is $self->{paths} - read
96 makes no attempt to guess what directories to look in. If the
97 namespace has no extension the extension listed in
98 $args->{default_ext} or $self->{default_ext} or $DEFAULT_EXT will
99 be used).
100 my $ref = $cob->read('My::NameSpace', {
102 paths => [qw(/tmp /usr/data)],
103 default_ext => 'pl',
104 });
105 # would look first for /tmp/My/NameSpace.pl
106 # and then /usr/data/My/NameSpace.pl
107 my $ref = $cob->read('foo.sto', {
109 paths => [qw(/tmp /usr/data)],
110 default_ext => 'pl',
111 });
112 # would look first for /tmp/foo.sto
113 # and then /usr/data/foo.sto
114 When a namespace is used and there are multiple possible paths,
116 there area a few options to control which file to look for. A
117 directive of 'FIRST', 'MERGE', or 'LAST' may be specified in
118 $args->{directive} or $self->{directive} or the default value in
119 $DIRECTIVE will be used (default is 'LAST'). When 'FIRST' is
120 specified the first path that contains the namespace is returned.
121 If 'LAST' is used, the last found path that contains the namespace
122 is returned. If 'MERGE' is used, the data structures are joined
123 together. If they are arrayrefs, they are joined into one large
124 arrayref. If they are hashes, they are layered on top of each
125 other with keys found in later paths overwriting those found in
126 earlier paths. This allows for setting system defaults in a root
127 file, and then allow users to have custom overrides.
128 It is possible to make keys in a root file be immutable (non
130 overwritable) by adding a suffix of _immutable or _immu to the key
131 (ie {foo_immutable => 'bar'}). If a value is found in the file
132 that matches $IMMUTABLE_KEY, the entire file is considered
133 immutable. The immutable defaults may be overriden using
134 $IMMUTABLE_QR and $IMMUTABLE_KEY.
135 Errors during read die. If the file does not exist undef is
137 returned.
138 "write_ref"
140 Takes a file and the reference to be written. Figures out the type
141 of handler to use to write the file and writes it. If you used the
142 ->read_ref use this method. Otherwise, use ->write.
143 "write"
145 Allows for writing back out the information read in by ->read. If
146 multiple paths where used - the directive 'FIRST' will write the
147 changes to the first file in the path - otherwise the last path
148 will be used. If ->read had found immutable keys, then those keys
149 are removed before writing.
150 Errors during write die.
152 "preload_files"
154 Arguments are file(s) and/or directory(s) to preload.
155 preload_files will loop through the arguments, find the files that
156 exist, read them in using the handler which matches the files
157 extension, and cache them by filename in %CACHE. Directories are
158 spidered for file extensions which match those listed in
159 %EXT_READERS. This is useful for a server environment where CPU
160 may be more precious than memory.
161 "in_cache"
163 Allow for testing if a particular filename is registered in the
164 %CACHE - typically from a preload_files call. This is useful when
165 building wrappers around the conf_read and conf_write method calls.
166
168 conf_read
169 Takes a filename. Returns the read contents of that filename. The
170 handler to use is based upon the extention on the file.
171 my $hash = conf_read('/tmp/foo.yaml');
173 my $hash = conf_read('/tmp/foo', {file_type => 'yaml'});
175 Takes a filename and a data structure. Writes the data to the
177 filename. The handler to use is based upon the extention on the
178 file.
179 conf_write('/tmp/foo.yaml', \%hash);
181 conf_write('/tmp/foo', \%hash, {file_type => 'yaml'});
183
185 CGI::Ex::Conf supports the files found in %EXT_READERS by default.
186 Additional types may be added to %EXT_READERS, or a custom handler may
187 be passed via $args->{handler} or $self->{handler}. If the custom
188 handler is a code ref, all files will be passed to it. If it is a
189 hashref, it should contain keys which are extensions it supports, and
190 values which read those extensions.
191 Some file types have benefits over others. Storable is very fast, but
193 is binary and not human readable. YAML is readable but very slow. I
194 would suggest using a readable format such as YAML and then using
195 preload_files to load in what you need at run time. All preloaded
196 files are faster than any of the other types.
197 The following is the list of handlers that ships with CGI::Ex::Conf
199 (they will only work if the supporting module is installed on your
200 system):
201 "pl"
203 Should be a file containing a perl structure which is the last
204 thing returned.
205 "sto" and "storable"
207 Should be a file containing a structure stored in Storable format.
208 See Storable.
209 "yaml" and "conf" and "val"
211 Should be a file containing a yaml document. Multiple documents
212 are returned as a single arrayref. Also - any file without an
213 extension and custom handler will be read using YAML. See YAML.
214 "ini"
216 Should be a windows style ini file. See Config::IniHash
217 "xml"
219 Should be an xml file. It will be read in by XMLin. See
220 XML::Simple.
221 "json"
223 Should be a json file. It will be read using the JSON library.
224 See JSON.
225 "html" and "htm"
227 This is actually a custom type intended for use with
228 CGI::Ex::Validate. The configuration to be read is actually
229 validation that is stored inline with the html. The handler will
230 look for any form elements or input elements with an attribute with
231 the same name as in $HTML_KEY. It will also look for a javascript
232 variable by the same name as in $HTML_KEY. All configuration items
233 done this way should be written in YAML. For example, if $HTML_KEY
234 contained 'validation' it would find validation in:
235 <input type=text name=username validation="{required: 1}">
237 # automatically indented and "username:\n" prepended
238 # AND #
239 <form name=foo validation="
240 general no_confirm: 1
241 ">
242 # AND #
243 <script>
244 document.validation = "\n\
245 username: {required: 1}\n\
246 ";
247 </script>
248 # AND #
249 <script>
250 var validation = "\n\
251 username: {required: 1}\n\
252 ";
253 </script>
254 If the key $HTML_KEY is not set, the handler will always return
256 undef without even opening the file.
257
259 Make a similar write method that handles immutability.
260
262 This module may be distributed under the same terms as Perl itself.
263
265 Paul Seamons <perl at seamons dot com>
266perl v5.32.1 2021-01-26 CGI::Ex::Conf(3)