#!ff needs \ $Id: hello,v 1.1 2006/05/08 19:55:06 lavarenn Exp $ \ Any text after backslash+space is a comment to end-of-line. \ This file is executable by the shell (/bin/sh or other) \ thanks to its first two characters (#!) which trigger the \ shell to execute the command "ff needs ./thisfilename" \ (where thisfilename is a placeholder for this file's name). \ This triggers ff to load (at tib) and evaluate the string \ "needs ./thisfilename", then needs loads (after the string) \ thisfilename contents, skips its first line if beginning with #!, \ then evaluates the rest: if this ever returns, then ff enters \ the user interaction loop (repeat prompt read compiler again). ."hello_world!" bye As "bye" returns from ff to the shell, the remaining of this file contents after "bye" is ignored by ff.