Linux - Is there a way to convert .bz2 files to .tar.bz2 files using pipes?

Linux - Is there a way to convert .bz2 files to .tar.bz2 files using pipes?

Is there a way to convert a .bz2 file to a .tar.bz2 file without decompressing the entire thing to disk and then re-compressing? The decompressed size is larger than my drive. Since bz2 operates on blocks, it would seem like you could just decompress a block, pipe it, re-compress it, remove the decompressed block from memory, etc.

Asked by: Guest | Views: 362

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Guest [Entry]

"Update: My original answer doesn't work at all, sorry. tar won't accept a data stream from STDIN as input, so the first command fails.

The only way I can think of to accomplish what you want is to write your own program to add the required tar headers and such around your data stream. Then you could write:

$ bzcat foo.bz2 | stream-to-tar | bzip - > foo.tar.bz2

... and (assuming your program gets the tar format right) you could decompress it with a standard tar xf foo.tar.bz2.

This probably isn't how you want to do it, since it doesn't provide any of the usual advantages of tar'ing the file in the first place.

$ bzcat foo.bz2 | tar cjf foo.tar.bz2 -

Now, the problem is that tar doesn't include any filesystem in it cause all we've given it is a decompressed data stream. That means you need to decompress/untar it like this:

$ tar --to-stdout -xjf foo.tar.bz2 > foo"