help

早期freebsd实现

For more information while running calc, type  help  followed by one of the
following topics:

	topic		description
	-----		-----------
	intro		introduction to calc
	overview	overview of calc
	help		this file

	assoc		using associations
	builtin		builtin functions
	command		top level commands
	config		configuration parameters
	define		how to define functions
	environment	how environment variables effect calc
	expression	expression sequences
	file		using files
	history		command history
	interrupt	how interrupts are handled
	list		using lists
	mat		using matrices
	obj		user defined data types
	operator	math, relational, logic and variable access operators
	statement	flow control and declaration statements
	stdlib		description of some lib files shipped with calc
	types		builtin data types
	usage		how to invoke the calc command
	variable	variables and variable declarations

	bindings	input & history character bindings
	altbind		alternative input & history character bindings
	changes		recent changes to calc
	libcalc		using the arbitrary precision routines in a C program
	stdlib		standard calc library files and standards
	bugs		known bugs and mis-features
	todo		needed enhancements and wish list
	credit		who wrote calc and who helped

	full		all of the above

For example:

	help usage

will print the calc command usage information.  One can obtain calc help
without invoking any startup code by running calc as follows:

	calc -q help topic

where 'topic' is one of the topics listed above.