Support for split archives

I could use mounting split tar archive created like this: tar cf - ./folder | split --bytes=500MB - archive.tar.

[mxmlnkn]

I implemented a prototype on the develop branch. You can try it out with:

python3 -m pip install --user --force-reinstall 'git+https://github.com/mxmlnkn/ratarmount.git@develop#egginfo=ratarmountcore&subdirectory=core'
python3 -m pip install --user 'git+https://github.com/mxmlnkn/ratarmount.git@develop#egginfo=ratarmount'

It can detect decimal, hexadecimal, and alphabetical split extensions of arbitrary length. But it assumes that the split extension sequence either begins at 0 or 1 even though split theoretically allows setting FROM higher than 1. Furthermore, by default split will create files without any dot but ratarmount will only look for extensions, i.e., the prefix given to split is required to end with . for compatibility.

It does not yet work recursively if there is a split archive inside another archive but I’ll probably implement that before a release.

I also decided to make the split file detection the default behavior and offer a --no-detect-split option. This option is also not yet implemented.

You can try it out with:

base64 /dev/urandom | head -c $(( 64 * 1024 )) > random
tar -cf- random | split --bytes=32K --numeric-suffixes=1 --suffix-length=3 - random.tar.
ls -la
# random.tar.001
# random.tar.002
# random.tar.003
ratarmount random.tar.001 mountPoint
diff -s random mountPoint/random
# Files random and mountPoint/random are identical

In this example, I specified the .001 file but it also works with any other part, e.g., .002. It even should work when specifying all of the parts ratarmount random.tar.[0-9][0-9][0-9] mountPoint. But the parts should not be interspersed with other archives to be union mounted because the order is important for the resulting merged view. E.g.: ratarmount foo.tar random.tar.001 bar.tar random.tar.002 mountPoint. In that case, ratarmount will print an error because the “same” random.tar archive appears at conflicting positions.

[mxmlnkn]

Closed with d5bb6e4 in master. The release should follow in the next weeks.