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duop - Dump Opera Files

Since becoming just another Chrome-based browser, Opera no longer uses files in this format. This was one of the worst-designed binary file formats I've ever seen, but, in fairness, it's the kind of binary format a lot of programmers would come up with. Part of the problem was the obvious attempt to design a format portable to different platforms, but the resulting complexity was crazy — and completely unnecessary. I would blame it on the increasing number of programmers divorced from programming down to the bare metal, but binary file formats in the "old days" weren't always much better as I remember.

duop dumps binary files used by the original Opera web browser. The file format (definition, Wayback Machine) was used for the cookies file ("cookies4.dat"), the download rescue file ("download.dat"), and the visited links file ("vlink4.dat"). The format was supposedly used for the disk cache files, but I never saw any likely candidates in my Opera 9 cache directories.

The output of duop is currently Scheme-friendly S-expressions.


% duop [-debug]
       [-cache] [-cookies] [-download] [-index] [-visited]


writes debug information to standard output.
specify the type of Opera file being dumped. By default, duop attempts to determine the file type based on the tag ID in the record following the header record.
is the file to dump; if no file is specified, input is read from standard input.

Alex Measday  /  E-mail