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
7
9 use CGI::Ex::Conf qw(conf_read conf_write);
10 my $hash = conf_read("/tmp/foo.yaml");
12 conf_write("/tmp/foo.yaml", {key1 => $val1, key2 => $val2});
14 ### OOP interface
17 my $cob = CGI::Ex::Conf->new;
19 my $full_path_to_file = "/tmp/foo.val"; # supports ini, sto, val, pl, xml
21 my $hash = $cob->read($file);
22 local $cob->{default_ext} = 'conf'; # default anyway
24 my @paths = qw(/tmp, /home/pauls);
27 local $cob->{paths} = \@paths;
28 my $hash = $cob->read('My::NameSpace');
29 # will look in /tmp/My/NameSpace.conf and /home/pauls/My/NameSpace.conf
30 my $hash = $cob->read('My::NameSpace', {paths => ['/tmp']});
33 # will look in /tmp/My/NameSpace.conf
34 local $cob->{directive} = 'MERGE';
37 my $hash = $cob->read('FooSpace');
38 # OR #
39 my $hash = $cob->read('FooSpace', {directive => 'MERGE'});
40 # will return merged hashes from /tmp/FooSpace.conf and /home/pauls/FooSpace.conf
41 # immutable keys are preserved from originating files
42 local $cob->{directive} = 'FIRST';
45 my $hash = $cob->read('FooSpace');
46 # will return values from first found file in the path.
47 local $cob->{directive} = 'LAST'; # default behavior
50 my $hash = $cob->read('FooSpace');
51 # will return values from last found file in the path.
52 ### manipulate $hash
55 $cob->write('FooSpace'); # will write it out the changes
56
58 There are half a million Conf readers out there. Why not add one more.
59 Actually, this module provides a wrapper around the many file formats
60 and the config modules that can handle them. It does not introduce any
61 formats of its own.
62 This module also provides a preload ability which is useful in
64 conjunction with mod_perl.
65 Oh - and it writes too.
67
69 "read_ref"
70 Takes a file and optional argument hashref. Figures out the type
71 of handler to use to read the file, reads it and returns the ref.
72 If you don't need the extended merge functionality, or key
73 fallback, or immutable keys, or path lookup ability - then use this
74 method. Otherwise - use ->read.
75 "read"
77 First argument may be either a perl data structure, yaml string, a
78 full filename, or a file "namespace".
79 The second argument can be a hashref of override values (referred
81 to as $args below)..
82 If the first argument is a perl data structure, it will be copied
84 one level deep and returned (nested structures will contain the
85 same references). A yaml string will be parsed and returned. A
86 full filename will be read using the appropriate handler and
87 returned (a file beginning with a / or ./ or ../ is considered to
88 be a full filename). A file "namespace" (ie "footer" or
89 "my::config" or "what/ever") will be turned into a filename by
90 looking for that namespace in the paths found either in
91 $args->{paths} or in $self->{paths} or in @DEFAULT_PATHS.
92 @DEFAULT_PATHS is empty by default as is $self->{paths} - read
93 makes no attempt to guess what directories to look in. If the
94 namespace has no extension the extension listed in
95 $args->{default_ext} or $self->{default_ext} or $DEFAULT_EXT will
96 be used).
97 my $ref = $cob->read('My::NameSpace', {
99 paths => [qw(/tmp /usr/data)],
100 default_ext => 'pl',
101 });
102 # would look first for /tmp/My/NameSpace.pl
103 # and then /usr/data/My/NameSpace.pl
104 my $ref = $cob->read('foo.sto', {
106 paths => [qw(/tmp /usr/data)],
107 default_ext => 'pl',
108 });
109 # would look first for /tmp/foo.sto
110 # and then /usr/data/foo.sto
111 When a namespace is used and there are multiple possible paths,
113 there area a few options to control which file to look for. A
114 directive of 'FIRST', 'MERGE', or 'LAST' may be specified in
115 $args->{directive} or $self->{directive} or the default value in
116 $DIRECTIVE will be used (default is 'LAST'). When 'FIRST' is
117 specified the first path that contains the namespace is returned.
118 If 'LAST' is used, the last found path that contains the namespace
119 is returned. If 'MERGE' is used, the data structures are joined
120 together. If they are arrayrefs, they are joined into one large
121 arrayref. If they are hashes, they are layered on top of each
122 other with keys found in later paths overwriting those found in
123 earlier paths. This allows for setting system defaults in a root
124 file, and then allow users to have custom overrides.
125 It is possible to make keys in a root file be immutable (non
127 overwritable) by adding a suffix of _immutable or _immu to the key
128 (ie {foo_immutable => 'bar'}). If a value is found in the file
129 that matches $IMMUTABLE_KEY, the entire file is considered
130 immutable. The immutable defaults may be overriden using
131 $IMMUTABLE_QR and $IMMUTABLE_KEY.
132 Errors during read die. If the file does not exist undef is
134 returned.
135 "write_ref"
137 Takes a file and the reference to be written. Figures out the type
138 of handler to use to write the file and writes it. If you used the
139 ->read_ref use this method. Otherwise, use ->write.
140 "write"
142 Allows for writing back out the information read in by ->read. If
143 multiple paths where used - the directive 'FIRST' will write the
144 changes to the first file in the path - otherwise the last path
145 will be used. If ->read had found immutable keys, then those keys
146 are removed before writing.
147 Errors during write die.
149 "preload_files"
151 Arguments are file(s) and/or directory(s) to preload.
152 preload_files will loop through the arguments, find the files that
153 exist, read them in using the handler which matches the files
154 extension, and cache them by filename in %CACHE. Directories are
155 spidered for file extensions which match those listed in
156 %EXT_READERS. This is useful for a server environment where CPU
157 may be more precious than memory.
158 "in_cache"
160 Allow for testing if a particular filename is registered in the
161 %CACHE - typically from a preload_files call. This is useful when
162 building wrappers around the conf_read and conf_write method calls.
163
165 conf_read
166 Takes a filename. Returns the read contents of that filename. The
167 handler to use is based upon the extention on the file.
168 my $hash = conf_read('/tmp/foo.yaml');
170 my $hash = conf_read('/tmp/foo', {file_type => 'yaml'});
172 Takes a filename and a data structure. Writes the data to the
174 filename. The handler to use is based upon the extention on the
175 file.
176 conf_write('/tmp/foo.yaml', \%hash);
178 conf_write('/tmp/foo', \%hash, {file_type => 'yaml'});
180
182 CGI::Ex::Conf supports the files found in %EXT_READERS by default.
183 Additional types may be added to %EXT_READERS, or a custom handler may
184 be passed via $args->{handler} or $self->{handler}. If the custom
185 handler is a code ref, all files will be passed to it. If it is a
186 hashref, it should contain keys which are extensions it supports, and
187 values which read those extensions.
188 Some file types have benefits over others. Storable is very fast, but
190 is binary and not human readable. YAML is readable but very slow. I
191 would suggest using a readable format such as YAML and then using
192 preload_files to load in what you need at run time. All preloaded
193 files are faster than any of the other types.
194 The following is the list of handlers that ships with CGI::Ex::Conf
196 (they will only work if the supporting module is installed on your
197 system):
198 "pl"
200 Should be a file containing a perl structure which is the last
201 thing returned.
202 "sto" and "storable"
204 Should be a file containing a structure stored in Storable format.
205 See Storable.
206 "yaml" and "conf" and "val"
208 Should be a file containing a yaml document. Multiple documents
209 are returned as a single arrayref. Also - any file without an
210 extension and custom handler will be read using YAML. See YAML.
211 "ini"
213 Should be a windows style ini file. See Config::IniHash
214 "xml"
216 Should be an xml file. It will be read in by XMLin. See
217 XML::Simple.
218 "json"
220 Should be a json file. It will be read using the JSON library.
221 See JSON.
222 "html" and "htm"
224 This is actually a custom type intended for use with
225 CGI::Ex::Validate. The configuration to be read is actually
226 validation that is stored inline with the html. The handler will
227 look for any form elements or input elements with an attribute with
228 the same name as in $HTML_KEY. It will also look for a javascript
229 variable by the same name as in $HTML_KEY. All configuration items
230 done this way should be written in YAML. For example, if $HTML_KEY
231 contained 'validation' it would find validation in:
232 <input type=text name=username validation="{required: 1}">
234 # automatically indented and "username:\n" prepended
235 # AND #
236 <form name=foo validation="
237 general no_confirm: 1
238 ">
239 # AND #
240 <script>
241 document.validation = "\n\
242 username: {required: 1}\n\
243 ";
244 </script>
245 # AND #
246 <script>
247 var validation = "\n\
248 username: {required: 1}\n\
249 ";
250 </script>
251 If the key $HTML_KEY is not set, the handler will always return
253 undef without even opening the file.
254
256 Make a similar write method that handles immutability.
257
259 This module may be distributed under the same terms as Perl itself.
260
262 Paul Seamons <perl at seamons dot com>
263perl v5.28.1 2018-12-07 CGI::Ex::Conf(3)