Palm::PDB(3pm)

1Palm::PDB(3)          User Contributed Perl Documentation         Palm::PDB(3)
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3
4

NAME

6       Palm::PDB - Parse Palm database files
7

VERSION

9       This document describes version 1.400 of Palm::PDB, released March 7,
10       2015 as part of Palm-PDB version 1.400.
11

SYNOPSIS

13           use Palm::PDB;
14           use SomeHelperClass;
15
16           $pdb = Palm::PDB->new;
17           $pdb->Load("myfile.pdb");
18
19           # Manipulate records in $pdb
20
21           $pdb->Write("myotherfile.pdb");
22
23       (Note: yes, you do want to use "Palm::PDB", even if you're dealing with
24       some other type of database. $pdb will be reblessed to the appropriate
25       type by "$pdb->Load".)
26

DESCRIPTION

28       The Palm::PDB module provides a framework for reading and writing
29       database files for use on PalmOS devices such as the PalmPilot. It can
30       read and write both Palm Database (".pdb") and Palm Resource (".prc")
31       files.
32
33       By itself, the PDB module is not terribly useful; it is intended to be
34       used in conjunction with supplemental modules for specific types of
35       databases, such as Palm::Raw or Palm::Memo.
36
37       The Palm::PDB module encapsulates the common work of parsing the
38       structure of a Palm database. The Load() function reads the file, then
39       passes the individual chunks (header, records, etc.) to application-
40       specific functions for processing. Similarly, the Write() function
41       calls application-specific functions to get the individual chunks, then
42       writes them to a file.
43

METHODS

45   new
46         $new = Palm::PDB->new;
47
48       Creates a new PDB. $new is a reference to an anonymous hash. Some of
49       its elements have special significance. See Load().
50
51   RegisterPDBHandlers
52         &Palm::PDB::RegisterPDBHandlers("classname", typespec...);
53
54       Typically:
55
56         &Palm::PDB::RegisterPDBHandlers(__PACKAGE__,
57               [ "FooB", "DATA" ],
58               );
59
60       The $pdb->Load() method acts as a virtual constructor. When it reads
61       the header of a ".pdb" file, it looks up the file's creator and type in
62       a set of tables, and reblesses $pdb into a class capable of parsing the
63       application-specific parts of the file (AppInfo block, records, etc.)
64
65       RegisterPDBHandlers() adds entries to these tables; it says that any
66       file whose creator and/or type match any of the typespecs (there may be
67       several) should be reblessed into the class classname.
68
69       Note that RegisterPDBHandlers() applies only to record databases
70       (".pdb" files). For resource databases, see RegisterPRCHandlers().
71
72       RegisterPDBHandlers() is typically called in the import() function of a
73       helper class. In this case, the class is registering itself, and it is
74       simplest just to use "__PACKAGE__" for the package name:
75
76           package PalmFoo;
77           use Palm::PDB;
78
79           sub import
80           {
81               &Palm::PDB::RegisterPDBHandlers(__PACKAGE__,
82                   [ "FooZ", "DATA" ]
83                   );
84           }
85
86       A typespec can be either a string, or an anonymous array with two
87       elements. If it is an anonymous array, then the first element is the
88       file's creator; the second element is its type. If a typespec is a
89       string, it is equivalent to specifying that string as the database's
90       creator, and a wildcard as its type.
91
92       The creator and type should be either four-character strings, or the
93       empty string. An empty string represents a wildcard. Thus:
94
95           &Palm::PDB::RegisterPDBHandlers("MyClass",
96               [ "fOOf", "DATA" ],
97               [ "BarB", "" ],
98               [ "", "BazQ" ],
99               "Fred"
100               );
101
102       Class MyClass will handle:
103
104       •   Databases whose creator is "fOOf" and whose type is "DATA".
105
106       •   Databases whose creator is "BarB", of any type.
107
108       •   Databases with any creator whose type is "BazQ".
109
110       •   Databases whose creator is "Fred", of any type.
111
112   RegisterPRCHandlers
113         &Palm::PDB::RegisterPRCHandlers("classname", typespec...);
114
115       Typically:
116
117         &Palm::PDB::RegisterPRCHandlers(__PACKAGE__,
118               [ "FooZ", "CODE" ],
119               );
120
121       RegisterPRCHandlers() is similar to RegisterPDBHandlers(), but
122       specifies a class to handle resource database (".prc") files.
123
124       A class for parsing applications should begin with:
125
126           package PalmApps;
127           use Palm::PDB;
128
129           sub import
130           {
131               &Palm::PDB::RegisterPRCHandlers(__PACKAGE__,
132                   [ "", "appl" ]
133                   );
134           }
135
136   Load
137         $pdb->Load($filename);
138
139       Reads the file $filename, parses it, reblesses $pdb to the appropriate
140       class, and invokes appropriate methods to parse the application-
141       specific parts of the database (see "HELPER CLASS METHODS").
142
143       $filename may also be an open file handle (as long as it's seekable).
144       This allows for manipulating databases in memory structures.
145
146       Load() uses the typespecs given to RegisterPDBHandlers() and
147       RegisterPRCHandlers() when deciding how to rebless $pdb. For record
148       databases, it uses the typespecs passed to RegisterPDBHandlers(), and
149       for resource databases, it uses the typespecs passed to
150       RegisterPRCHandlers().
151
152       Load() looks for matching typespecs in the following order, from most
153       to least specific:
154
155       1.  A typespec that specifies both the database's creator and its type
156           exactly.
157
158       2.  A typespec that specifies the database's type and has a wildcard
159           for the creator (this is rarely used).
160
161       3.  A typespec that specifies the database's creator and has a wildcard
162           for the type.
163
164       4.  A typespec that has wildcards for both the creator and type.
165
166       Thus, if the database has creator "FooZ" and type "DATA", Load() will
167       first look for "FooZ"/"DATA", then ""/"DATA", then "FooZ"/"", and
168       finally will fall back on ""/"" (the universal default).
169
170       After Load() returns, $pdb may contain the following fields:
171
172       $pdb->{"name"}
173           The name of the database.
174
175       $pdb->{"attributes"}{"ResDB"}
176       $pdb->{"attributes"}{"ReadOnly"}
177       $pdb->{"attributes"}{"AppInfoDirty"}
178       $pdb->{"attributes"}{"Backup"}
179       $pdb->{"attributes"}{"OKToInstallNewer"}
180       $pdb->{"attributes"}{"ResetAfterInstall"}
181       $pdb->{"attributes"}{"CopyPrevention"}
182       $pdb->{"attributes"}{"Stream"}
183       $pdb->{"attributes"}{"Hidden"}
184       $pdb->{"attributes"}{"LaunchableData"}
185       $pdb->{"attributes"}{"Recyclable"}
186       $pdb->{"attributes"}{"Bundle"}
187       $pdb->{"attributes"}{"Open"}
188           These are the attribute flags from the database header. Each is
189           true iff the corresponding flag is set.
190
191           The "LaunchableData" attribute is set on PQAs.
192
193       $pdb->{"version"}
194           The database's version number. An integer.
195
196       $pdb->{"ctime"}
197       $pdb->{"mtime"}
198       $pdb->{"baktime"}
199           The database's creation time, last modification time, and time of
200           last backup, in Unix "time_t" format (seconds since Jan. 1, 1970).
201
202       $pdb->{"modnum"}
203           The database's modification number. An integer.
204
205       $pdb->{"type"}
206           The database's type. A four-character string.
207
208       $pdb->{"creator"}
209           The database's creator. A four-character string.
210
211       $pdb->{"uniqueIDseed"}
212           The database's unique ID seed. An integer.
213
214       $pdb->{"2NULs"}
215           The two NUL bytes that appear after the record index and the
216           AppInfo block. Included here because every once in a long while,
217           they are not NULs, for some reason.
218
219       $pdb->{"appinfo"}
220           The AppInfo block, as returned by the $pdb->ParseAppInfoBlock()
221           helper method.
222
223       $pdb->{"sort"}
224           The sort block, as returned by the $pdb->ParseSortBlock() helper
225           method.
226
227       @{$pdb->{"records"}}
228           The list of records in the database, as returned by the
229           $pdb->ParseRecord() helper method. Resource databases do not have
230           this.
231
232       @{$pdb->{"resources"}}
233           The list of resources in the database, as returned by the
234           $pdb->ParseResource() helper method. Record databases do not have
235           this.
236
237       All of these fields may be set by hand, but should conform to the
238       format given above.
239
240   Write
241         $pdb->Write($filename);
242
243       Invokes methods in helper classes to get the application-specific parts
244       of the database, then writes the database to the file $filename.
245
246       $filename may also be an open file handle (as long as it's seekable).
247       This allows for manipulating databases in memory structures.
248
249       Write() uses the following helper methods:
250
251       PackAppInfoBlock()
252       PackSortBlock()
253       PackResource() or PackRecord()
254
255       See also "HELPER CLASS METHODS".
256
257   new_Record
258         $record = Palm::PDB->new_Record();
259
260       Creates a new record, with the bare minimum needed:
261
262               $record->{'category'}
263               $record->{'attributes'}{'Dirty'}
264               $record->{'id'}
265
266       The ``Dirty'' attribute is originally set, since this function will
267       usually be called to create records to be added to a database.
268
269       "new_Record" does not add the new record to a PDB. For that, you want
270       "append_Record".
271
272   is_Dirty
273         $pdb->Write( $fname ) if $pdb->is_Dirty();
274
275       Returns non-zero if any of the in-memory elements of the database have
276       been changed. This includes changes via function calls (any call that
277       changes the $pdb's "last modification" time) as well as testing the
278       "dirty" status of attributes where possible (i.e. AppInfo, records, but
279       not resource entries).
280
281   append_Record
282         $record  = $pdb->append_Record;
283         $record2 = $pdb->append_Record($record1);
284
285       If called without any arguments, creates a new record with
286       new_Record(), and appends it to $pdb.
287
288       If given a reference to a record, appends that record to
289       @{$pdb->{records}}.
290
291       Returns a reference to the newly-appended record.
292
293       This method updates $pdb's "last modification" time.
294
295   new_Resource
296         $resource = Palm::PDB->new_Resource();
297
298       Creates a new resource and initializes
299
300               $resource->{type}
301               $resource->{id}
302
303   append_Resource
304         $resource  = $pdb->append_Resource;
305         $resource2 = $pdb->append_Resource($resource1);
306
307       If called without any arguments, creates a new resource with
308       new_Resource(), and appends it to $pdb.
309
310       If given a reference to a resource, appends that resource to
311       @{$pdb->{resources}}.
312
313       Returns a reference to the newly-appended resource.
314
315       This method updates $pdb's "last modification" time.
316
317   findRecordByID
318         $record = $pdb->findRecordByID($id);
319
320       Looks through the list of records in $pdb, and returns a reference to
321       the record with ID $id, or the undefined value if no such record was
322       found.
323
324   delete_Record
325         $pdb->delete_Record($record, $expunge);
326
327       Marks $record for deletion, so that it will be deleted from the
328       database at the next sync.
329
330       If $expunge is false or omitted, the record will be marked for deletion
331       with archival. If $expunge is true, the record will be marked for
332       deletion without archival.
333
334       This method updates $pdb's "last modification" time.
335
336   remove_Record
337               for (@{ $pdb->{'records'} })
338               {
339                       $pdb->remove_Record( $_ ) if $_->{attributes}{deleted};
340               }
341
342       Removes $record from the database. This differs from "delete_Record" in
343       that it's an actual deletion rather than just setting a flag.
344
345       This method updates $pdb's "last modification" time.
346

HELPER CLASS METHODS

348       "$pdb->Load()" reblesses $pdb into a new class. This helper class is
349       expected to convert raw data from the database into parsed
350       representations of it, and vice-versa.
351
352       A helper class must have all of the methods listed below. The Palm::Raw
353       class is useful if you don't want to define all of the required
354       methods.
355
356   ParseAppInfoBlock
357         $appinfo = $pdb->ParseAppInfoBlock($buf);
358
359       $buf is a string of raw data. ParseAppInfoBlock() should parse this
360       data and return it, typically in the form of a reference to an object
361       or to an anonymous hash.
362
363       This method will not be called if the database does not have an AppInfo
364       block.
365
366       The return value from ParseAppInfoBlock() will be accessible as
367       "$pdb->{appinfo}".
368
369   PackAppInfoBlock
370         $buf = $pdb->PackAppInfoBlock();
371
372       This is the converse of ParseAppInfoBlock(). It takes $pdb's AppInfo
373       block, "$pdb->{appinfo}", and returns a string of binary data that can
374       be written to the database file.
375
376   ParseSortBlock
377         $sort = $pdb->ParseSortBlock($buf);
378
379       $buf is a string of raw data. ParseSortBlock() should parse this data
380       and return it, typically in the form of a reference to an object or to
381       an anonymous hash.
382
383       This method will not be called if the database does not have a sort
384       block.
385
386       The return value from ParseSortBlock() will be accessible as
387       "$pdb->{sort}".
388
389   PackSortBlock
390         $buf = $pdb->PackSortBlock();
391
392       This is the converse of ParseSortBlock(). It takes $pdb's sort block,
393       "$pdb->{sort}", and returns a string of raw data that can be written to
394       the database file.
395
396   ParseRecord
397         $record = $pdb->ParseRecord(
398                 offset         => $offset,    # Record's offset in file
399                 attributes     =>             # Record attributes
400                     {
401                       expunged => bool,       # True iff expunged
402                       dirty    => bool,       # True iff dirty
403                       deleted  => bool,       # True iff deleted
404                       private  => bool,       # True iff private
405                       archive  => bool,       # True iff to be archived
406                     },
407                 category       => $category,  # Record's category number
408                 id             => $id,        # Record's unique ID
409                 data           => $buf,       # Raw record data
410               );
411
412       ParseRecord() takes the arguments listed above and returns a parsed
413       representation of the record, typically as a reference to a record
414       object or anonymous hash.
415
416       The output from ParseRecord() will be appended to "@{$pdb->{records}}".
417       The records appear in this list in the same order as they appear in the
418       file.
419
420       $offset argument is not normally useful, but is included for
421       completeness.
422
423       The fields in %$attributes are boolean values. They are true iff the
424       record has the corresponding flag set.
425
426       $category is an integer in the range 0-15, which indicates which
427       category the record belongs to. This is normally an index into a table
428       given at the beginning of the AppInfo block.
429
430       A typical ParseRecord() method has this general form:
431
432           sub ParseRecord
433           {
434               my $self = shift
435               my %record = @_;
436
437               # Parse $self->{data} and put the fields into new fields in
438               # $self.
439
440               delete $record{data};           # No longer useful
441               return \%record;
442           }
443
444   PackRecord
445         $buf = $pdb->PackRecord($record);
446
447       The converse of ParseRecord(). PackRecord() takes a record as returned
448       by ParseRecord() and returns a string of raw data that can be written
449       to the database file.
450
451       PackRecord() is never called when writing a resource database.
452
453   ParseResource
454         $record = $pdb->ParseResource(
455                 type   => $type,              # Resource type
456                 id     => $id,                # Resource ID
457                 offset => $offset,            # Resource's offset in file
458                 data   => $buf,               # Raw resource data
459               );
460
461       ParseResource() takes the arguments listed above and returns a parsed
462       representation of the resource, typically as a reference to a resource
463       object or anonymous hash.
464
465       The output from ParseResource() will be appended to
466       "@{$pdb->{resources}}". The resources appear in this list in the same
467       order as they appear in the file.
468
469       $type is a four-character string giving the resource's type.
470
471       $id is an integer that uniquely identifies the resource amongst others
472       of its type.
473
474       $offset is not normally useful, but is included for completeness.
475
476   PackResource
477         $buf = $pdb->PackResource($resource);
478
479       The converse of ParseResource(). PackResource() takes a resource as
480       returned by PackResource() and returns a string of raw data that can be
481       written to the database file.
482
483       PackResource() is never called when writing a record database.
484

CONFIGURATION AND ENVIRONMENT

504       Palm::PDB requires no configuration files or environment variables.
505

INCOMPATIBILITIES

507       None reported.
508

BUGS AND LIMITATIONS

510       These functions die too easily. They should return an error code.
511
512       Database manipulation is still an arcane art.
513
514       It may be possible to parse sort blocks further.
515

AUTHORS

517       Andrew Arensburger "<arensb AT ooblick.com>"
518
519       Currently maintained by Christopher J. Madsen "<perl AT cjmweb.net>"
520
521       Please report any bugs or feature requests to
522       "<bug-Palm-PDB AT rt.cpan.org>" or through the web interface at
523       <http://rt.cpan.org/Public/Bug/Report.html?Queue=Palm-PDB>.
524
525       You can follow or contribute to Palm-PDB's development at
526       <https://github.com/madsen/Palm-PDB>.
527

COPYRIGHT AND LICENSE

529       This software is copyright (c) 2000 by Andrew Arensburger.
530
531       This is free software; you can redistribute it and/or modify it under
532       the same terms as the Perl 5 programming language system itself.
533

DISCLAIMER OF WARRANTY

535       BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
536       FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT
537       WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
538       PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND,
539       EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
540       WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
541       ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
542       YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
543       NECESSARY SERVICING, REPAIR, OR CORRECTION.
544
545       IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
546       WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
547       REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENSE, BE LIABLE
548       TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR
549       CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
550       SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
551       RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
552       FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
553       SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
554       DAMAGES.
555
556
557
558perl v5.32.1                      2021-01-27                      Palm::PDB(3)