SHELL command
(SHELL command wordflag)

	Under Unix, outputs the result of running "command" as a shell
	command.  (The command is sent to /bin/sh, not csh or other
	alternatives.)  If the command is a literal list in the instruction
	line, and if you want a backslash character sent to the shell, you
	must use \\ to get the backslash through Logo's reader intact.  The
	output is a list containing one member for each line generated by
	the shell command.  Ordinarily each such line is represented by a
	list in the output, as though the line were read using READLIST.  If
	a second input is given, regardless of the value of the input, each
	line is represented by a word in the output as though it were read
	with READWORD.  Example:

			to dayofweek
			output first first shell [date]
			end

	This is "first first" to extract the first word of the first (and
	only) line of the shell output.

	Under MacOS X, SHELL works as under Unix.  SHELL is not available
	under Mac Classic.

	Under DOS, SHELL is a command, not an operation; it sends its
	input to a DOS command processor but does not collect the result
	of the command.

	Under Windows, the wxWidgets version of Logo behaves as under Unix (except
	that DOS-style commands are understood; use "dir" rather than "ls").
	The non-wxWidgets version behaves like the DOS version.