#!/bin/bash
# Simple include processor as an example of a dependency-logging command.
# sip input output depoutput
# Follows `include foo' at the beginning of a line.

exec 3>"$3"
exec >"$2"

function do_read {
	echo "$1" >&3
	[ -r "$1" ] || exit 1
	while IFS='' read line; do
		if [[ "$line" == "include "* ]]; then
			do_read "${line#include }"
		else
			echo "$line"
		fi
	done <"$1"
}

do_read "$1"