sharchive

sharchive: /shar'kiv/ n.  [UNIX and Usenet; from /bin/sh
   archive] A {flatten}ed representation of a set of one or more
   files, with the unique property that it can be unflattened (the
   original files restored) by feeding it through a standard UNIX
   shell; thus, a sharchive can be distributed to anyone running UNIX,
   and no special unpacking software is required.  Sharchives are also
   intriguing in that they are typically created by shell scripts; the
   script that produces sharchives is thus a script which produces
   self-unpacking scripts, which may themselves contain scripts.  (The
   downsides of sharchives are that they are an ideal venue for
   {Trojan horse} attacks and that, for recipients not running
   UNIX, no simple un-sharchiving program is possible; sharchives can
   and do make use of arbitrarily-powerful shell features.)
   Sharchives are also commonly referred to as `shar files' after the
   name of the most common program for generating them.