ext:*help-message* — Command line help messageext:*lisp-init-file-list* — ECL initialization files.ext:+default-command-arg-rules+ — ECL command line optionsext:command-args — List of command line arguments.ext:process-command-args — Process command line arguments.ext:quit — Exit ECL.ext:run-program — Start and communicate with a child process.ext:system — Invoke a command using the shell.ECL provides several facilities for invoking and communicating with
external processes. If one just wishes to execute some program, without
caring for its output, then probably ext:system is the best
function. In all other cases it is preferable to use ext:run-program, which opens pipes to communicate with the
program and manipulate it while it runs on the background.