Path: | README |
Last Update: | Mon Jan 09 00:43:28 +0000 2012 |
The ruby-ole library provides a variety of functions primarily for working with OLE2 structured storage files, such as those produced by Microsoft Office - eg *.doc, *.msg etc.
Here are some examples of how to use the library functionality, categorised roughly by purpose.
The recommended way to manipulate the contents is via the "file_system" API, whereby you use Ole::Storage instance methods similar to the regular File and Dir class methods.
ole = Ole::Storage.open('oleWithDirs.ole', 'rb+') p ole.dir.entries('.') # => [".", "..", "dir1", "dir2", "file1"] p ole.file.read('file1')[0, 25] # => "this is the entry 'file1'" ole.dir.mkdir('newdir')
Some convenience functions are provided for (currently read only) access to OLE property sets and other sources of meta data.
ole = Ole::Storage.open('test_word_95.doc') p ole.meta_data.file_format # => "MSWordDoc" p ole.meta_data.mime_type # => "application/msword" p ole.meta_data.doc_author.split.first # => "Charles"
This is probably of little interest to most developers using the library, but for some use cases you may need to drop down to the lower level API on which the "file_system" API is constructed, which exposes more of the format details.
Ole::Storage files can have multiple files with the same name, or with a slash in the name, and other things that are probably strictly invalid. This API is the only way to access those files.
You can access the header object directly:
p ole.header.num_sbat # => 1 p ole.header.magic.unpack('H*') # => ["d0cf11e0a1b11ae1"]
You can directly access the array of all Dirent objects, including the root:
p ole.dirents.length # => 5 puts ole.root.to_tree # => - #<Dirent:"Root Entry"> |- #<Dirent:"\001Ole" size=20 data="\001\000\000\002\000..."> |- #<Dirent:"\001CompObj" size=98 data="\001\000\376\377\003..."> |- #<Dirent:"WordDocument" size=2574 data="\334\245e\000-..."> \- #<Dirent:"\005SummaryInformation" size=54788 data="\376\377\000\000\001...">
You can access (through RangesIO methods, or by using the relevant Dirent and AllocationTable methods) information like where within the container a stream is located (these are offset/length pairs):
p ole.root["\001CompObj"].open { |io| io.ranges } # => [[0, 64], [64, 34]]
See the documentation for each class for more details.