Working with tarballs

We strongly encourage you to keep your code in a (private) hosted Git repository. Nonetheless, it is also useful to know how to create and move around “tarball” files. A tarball is a set of files packaged together into a single file, then compressed using the gzip compression program. “Tar” is short for “tape archive,” which tells you something about how long this particular mode of packaging files has been around! Most Unix software on the net is distributed as tarballs, and tarballs are also useful for moving around large binary files from place to place.

To create a tarball of all the files in the directory mystuff, type

tar czf mystuff.tgz mystuff

and to unpack the files, type

tar xzf mystuff.tgz

The mess of letters after the tar command tells the program what it is supposed to do; they have the following meanings:

• f filename: Specify the archive file name
• c: Create an archive file
• x: Extract an archive file
• z: Put an archive through gzip
• t: Get a table of contents for the archive
• v: Be verbose and tell me exactly what is happening

If you create a tarball on the cluster, you may want to use it to get a local copy on your laptop or home desktop. For this purpose, we recommend you use SFTP to move the files back and forth. If you are using a Linux machine or a Mac, you can open a terminal window and manipulate tarballs just as you would on the cluster. If you are on a Windows machine, you might be interested in using the Cygwin package, which provides a wide variety of Unix-style tools.