clic-rpi-image/scripts/dependencies_check

# dependencies_check
# $@	Dependency files to check
#
# Each dependency is in the form of a tool to test for, optionally followed by
# a : and the name of a package if the package on a Debian-ish system is not
# named for the tool (i.e., qemu-user-static).
dependencies_check()
{
	local depfile deps missing

	for depfile in "$@"; do
		if [[ -e "$depfile" ]]; then
			deps="$(sed -f "${SCRIPT_DIR}/remove-comments.sed" < "${BASE_DIR}/depends")"

		fi
		for dep in $deps; do
			if ! hash "${dep%:*}" 2>/dev/null; then
				missing="${missing:+$missing }${dep#*:}"
			fi
		done
	done

	if [[ "$missing" ]]; then
		echo "Required dependencies not installed"
		echo
		echo "This can be resolved on Debian/Raspbian systems by installing:"
		echo "$missing"
		false
	fi
}