shebang

from The Collaborative International Dictionary of English v.0.48

Shebang \She*bang"\, n. [Cf. {Shebeen}.]
   1. A jocosely depreciative name for a dwelling or shop; a
      primitive dwelling; a shanty. [Slang, U.S.]
      [1913 Webster]

   2. The structure of an object, process, organization, or
      anything viewed as complicated; -- used primarily in the
      phrase

   {the whole shebang}; as, it comes with unnecessary frills,
      but you have to buy the whole shebang. [informal]
      [PJC]

   3. (computers) [Possibly derived from shell bang; the
      character ! is referred to in some computer contexts as
      bang.] The character sequence #!, which frequently begins
      shell scripts in a Unix system.
      [PJC]

from Jargon File (4.4.4, 14 Aug 2003)

shebang
 /[email protected]/, n.

   [possibly a portmanteau of "sharp bang"] The character sequence "#!"
   that frequently begins executable shell scripts under Unix. Probably
   derived from "shell bang" under the influence of American slang "the
   whole shebang" (everything, the works).

from The Free On-line Dictionary of Computing (8 July 2008)

shebang

   <operating system> (Or "shebang line", "{bang path}")
   /sh*-bang'/ (From "{sharp}" and "{bang}") The {magic cookie}
   "#!" used in {Unix} to mark the start of a {script}, e.g. a
   {shell script} or {Perl script}.

   Under {Unix}, if the first two bytes of an {executable} file
   are "#!", the {kernel} treats the file as a script rather than
   a {machine code} program.  The word following the "!" (i.e.,
   everything up to the first {whitespace}) is used as the
   {pathname} of the {interpreter}.  For example, if the first
   line of an executable is

    #!/usr/local/bin/perl

   the script will be treated as a {Perl} script and passed as an
   argument to /usr/local/bin/perl to be interpreted.  Some
   variants of Unix also allow one or more parameters to be
   passed to the interpreter, for example, you can write

    #!/usr/bin/perl -w

   and the script will be started as if you typed

    /usr/bin/perl -w <filename>

   on the command line.  Also, most modern kernels ignore any
   whitespace between the "!" and the interpreter pathname.  Even
   some modern kernels have fairly small limits (e.g. 32) on the
   length of line they will accept, making long pathnames and
   arguments somewhat unportable.

   [Does anyone call this a "magic string"?]

   (1998-05-06)