How do I search for files which contain a specific text string?

[roxton]

1. You need to write your own encoding detection code or use something like enca library.
2. Write the ODT and DOC file parsers. Read files in the cycle, parse each file to extract the text, do the search. The ODT parser for the text extraction puproses only is a relatively simple thing. You need the XML parser and some unzipper for it.