How to unzip a multipart (spanned) ZIP on Linux?

You will need to join them first. You may use the common linux app, cat as in the example below:

cat test.zip* > ~/test.zip

This will concatenate all of your test.zip.001, test.zip.002, etc files into one larger, test.zip file. Once you have that single file, you may run unzip test.zip

"How to create, split, join and extract zip archives in Linux" may help.

The Linux unzip utility doesn't really support multipart zips. From the manual:

Multi-part archives are not yet supported, except in conjunction with zip. (All parts must be concatenated together in order, and then zip -F (for zip 2.x) or zip -FF (for zip 3.x) must be performed on the concatenated archive in order to “fix” it. Also, zip 3.0 and later can combine multi-part (split) archives into a combined single-file archive using zip -s- inarchive -O outarchive. See the zip 3 manual page for more information.)

So you need to first concatenate the pieces, then repair the result. cat test.zip.* concatenates all the files called test.zip.* where the wildcard * stands for any sequence of characters; the files are enumerated in lexicographic order, which is the same as numerical order thanks to the leadings zeroes. >test.zip directs the output into the file test.zip.

cat test.zip.* >test.zip
zip -FF test.zip --out test-full.zip
unzip test-full.zip

If you created the pieces by directly splitting the zip file, as opposed to creating a multi-part zip with the official Pkzip utility, all you need to do is join the parts.

cat test.zip.* >test.zip
unzip test.zip

7z x archive.zip.001

It will automatically find the rest