usage

早期freebsd实现

Calc command line

	Calc has the following command line:

		calc [-h] [-q] [calc_command ...]

		-h	print a help message  (equivalent to the
			help command)

		-q	By default, calc executes each file specified
			in the :-separated list found in the environment
			variable $CALCRC.  If $CALCRC does not exist,
			an internal default is used.

	If some calc_commands arguments are given on the command line,
	calc executes these commands and then exists.  If no command
	line arguments are given, calc prompts and reads commands
	from standard input.