start() {
        setup_switch() { return 0; }

        include /lib/network
        setup_switch
        ifup -a
        /sbin/wifi up
}

1. you can find the following code in /etc/init.d/network, i wonder why absolute path is used when call wifi, but not used when use ifup?
2. another question, which setup_switch function is called at last, since there is two defination of setup_swich, on  defined in start function, and the other defined in /lib/network script.