GNU Sharutils

GNU Sharutils is a set of utilities to handle shell archives. The shar utility produces a single file out of many files and prepares them for transmission by electronic mail services, for example by converting binary data files into plain ASCII text. A shell archive is a collection of files that can be unpacked by the sh shell. A wide range of features provide extensive flexibility in manufacturing shars and in specifying shar smartness. For example, shar may compress files, uuencode binary files, split long files and construct multi-part mailings, ensure correct unsharing order, and provide simplistic checksums.

GNU unshar scans a set of mail messages looking for the start of shell archives. It will automatically strip off the mail headers and other introductory text. The archive bodies are then unpacked by a copy of the shell. unshar may also process files containing concatenated shell archives.

You can find the manual at http://www.gnu.org/software/sharutils/manual/sharutils-4.2/