linux shell 脚本 判断一个文件是否 存在

/etc/init.d/rcS

#!/bin/sh 
# Start all init scripts in /etc/init.d
# executing them in numerical order.
#
for i in /etc/init.d/S??* ;do

     # Ignore dangling symlinks (if any).
     [ ! -f "$i" ] && continue

     case "$i" in
        *.sh)
            # Source shell script for speed.
            (
                trap - INT QUIT TSTP
                set start
                . $i
            )
            ;;
        *)
            # No sh extension, so fork subprocess.
            $i start
            ;;
    esac
done


if [ ! -f "/root/beijing.txt" ]; then
        if [ -f "/root/jinan.txt" ]; then
                ifconfig eth0 192.168.99.46
                route add default gw 192.168.99.1
                echo "nameserver 8.8.4.4">> /etc/resolv.conf
        fi
fi