depends

DEP_DIR="/usr/local/lib"

# Usage:
# Bash function libraries start with the line
# depends lib-1 lib-2
# And bash scripts start with the line
# source depends lib-1 lib-3

function depends {
	for dependency in "$@"
	do
		# this doesnt work on files with spaces
		[[ "$sourced" == *" $dependency "* ]] && continue
		[[ ! -f "${DEP_DIR}/$dependency" ]] && {
			echo "missing dependency: $dependency"
			exit
		}
		sourced+="$dependency "
		source "${DEP_DIR}/$dependency"
	done
}

sourced=" "
depends "$@"