shar makes so-called shell archives out of many files,
preparing them for transmission by electronic mail services.
A shell archive is a collection of files that can be unpacked by
/bin/sh. A wide range of features provide extensive flexibility
in manufacturing shars and in specifying shar smartness.
GNU unshar scans mail messages looking for the start of
a shell archive. This removes the mail headers and any lines
of correspondence. The body of the archive is then unpacked
by a copy of the shell. It can process multiple files at once.
It may also process files containing concatenated shell archives.