I create zip archives when I need to send them to the Windows people. And I usually have to split the archives because of the attachment size limit on email.
1. How to compress files with zip:
Syntax: zip name.zip file1 file2 file3
$ zip mike.zip file1 file2 file3
adding: file1 (stored 0%)
adding: file2 (stored 0%)
adding: file3 (stored 0%)
Compressing a single file only:
$ zip john.zip john01.jpg
adding: john01.jpg (stored 0%)
Zipping a directory:
Syntax: zip -r name.zip /path/to/dir
$ zip -r pictures ~/holidaypics
adding: home/razvan/holidaypics/ (stored 0%)
adding: home/razvan/holidaypics/pic1.jpg (stored 0%)
adding: home/razvan/holidaypics/pic3.jpg (stored 0%)
adding: home/razvan/holidaypics/pic2.jpg (stored 0%)
Creating a password protected archives (with the -e argument):
Sometimes you need to encrypt archives to protect the data inside. The receiver can only extract the files if he knows your password.
$ zip -e the_stevens.zip mike.doc sarah.doc
Enter password:
Verify password:
adding: mike.doc (stored 0%)
adding: sarah.doc (stored 0%)
Browsing zip archives:
There are a lot of tools for viewing the files inside an archive without extracting, but I recommand you to use ViM (yes, ViM!):
You can browse a password protected archive without knowing its password.
$ vim the_stevens
" zip.vim version v23
" Browsing zipfile /home/razvan/abc/the_stevens.zip
" Select a file with cursor and press ENTER
mike.doc
sarah.doc
[:q]
How to split files
I will split archives to 5 M each:
The tool for splitting zip archives is zipsplit, but I will use split because it splits any file type.
$ split -b 5M file1 --verbose
creating file `xaa'
creating file `xab'
creating file `xac'
creating file `xad'
creating file `xae'
The –verbose argument is not necesary. I put it only to show you what happens.
The splited files are named xaa, xab, … .
How to join files:
I will join the splited files with cat:
$ cat x* > ~/hugefile
$ ls ~/hugefile
/home/razvan/hugefile
Testing if an archive is OK or broken can be done with zip -T:
$ zip -T mike.zip
test of mike.zip OK
And finally:
Extracting files from a zip archive with unzip:
$ unzip mike.zip -d ~/output
Archive: mike.zip
extracting: /home/razvan/output/file1
extracting: /home/razvan/output/file2
extracting: /home/razvan/output/file3
You can also view the files inside an archive with unzip -l:
$ unzip -l mike.zip
Archive: mike.zip
Length Date Time Name
--------- ---------- ----- ----
0 2012-05-27 09:22 file1
0 2012-05-27 09:22 file2
0 2012-05-27 09:22 file3
--------- -------
0 3 files
If you need to extract only file2 from the mike.zip archive, do like this:
$ unzip mike.zip file2
Archive: mike.zip
extracting: file2
To unzip a password protected zip, you use the same unzip command, but you will have to type in the password:
$ unzip the_stevens.zip
Archive: the_stevens.zip
extracting: mike.doc
[the_stevens.zip] sarah.doc password:
extracting: sarah.doc