Add recovery record

ZIP archive (extension .zip) is used widely and 7-Zip archive (extension .7z) is useful. Because they don't have a feature of recovery record, someone might feel RAR archive is better. But, by using Parchive, normal ZIP or 7-Zip archive can be protected with recovery record also.

1: Create a ZIP or 7-Zip archive file.
ZIP or 7-Zip archive file
2: Create a single PAR2 file for the archive file.
PAR2 recovery file
3: With binary editor or Copy command, append the PAR2 file to the archive file. Then, the appended archive file contains recovery record.

The construction of the file is like below;
Original archive file Appended PAR2 recovery data

Because the file header is still the one of archive, it is treated as archive file, and it can be extract with normal archiver software. Because the file contains PAR2 packets, PAR2 client can treat it as PAR2 file also. As MultiPar can treat a PAR2 file which has different extension from ".par2", Drag&Drop the protected archive onto MultiPar short-cut icon will verify the archive file. On the MultiPar GUI, the archive with recovery record is shown as "Appended" status, when the original part of archive is complete.

Note, if you repair the archive, recovery record (appended PAR2 recovery data) will be removed. When you want to keep the PAR2 recovery data, you need to copy the file at first, and rename it to "something.par2", then open the "something.par2" by MultiPar (or QuickPar). Though you can split a protected archive into original part and recovery record by a binary editor, it is not easy task for normal users.

I think this method is useful to protect only one archive file. It is same as having two files (an archive file and its PAR2 file), but is convenient for transport / public / distribution as one ZIP/7-Zip file. Normally freeware/shareware publication site accepts only one archive file. If an archiver software has a built-in feature to append PAR2 recovery data to a created archive, it may be useful.