## whatis -- and implementation of the 10th Edition Unix sh builtin `whatis'#	    command.## usage: whatis arg [...]## For each argument, whatis prints the associated value as a parameter,# builtin, function, alias, or executable file as appropriate.  In each# case, the value is printed in a form which would yield the same value# if typed as input to the shell itself.#whatis(){	local wusage='usage: whatis arg [arg...]'	local fail=0	if [ $# -eq 0 ] ; then		echo "$wusage"		return 1	fi	for arg	do		case $(builtin type -type $arg 2>/dev/null) in		"alias")			builtin alias "$arg"			;;		"function")			builtin type "$arg" | sed 1d			;;		"builtin")			echo builtin "$arg"			;;		"file")			builtin type -path "$arg"			;;		*)			# OK, we could have a variable, or we could have nada			if [ "$(eval echo \${$arg+set})" = "set" ] ; then				# It is a variable, and it is set				echo -n "$arg="				eval echo '\"'\$$arg'\"'			else				echo whatis: $arg: not found				fail=1			fi			;;		esac	done	return $fail}