Shell自动修改CentOS6网卡配置文件

#!/bin/bash
#
MY_ONBOOT="ONBOOT=yes"
MY_BOOTPROTO="BOOTPROTO=static"
MY_DEVICE="DEVICE="`ifconfig -a|grep HWaddr|awk {'print $1'}`
MY_HWADDR="HWADDR="`ifconfig -a|grep HWaddr|awk {'print $5'}`
MY_IPADDR="IPADDR="$1
MY_NETMASK="NETMASK="$2
MY_GATEWAY="GATEWAY="$3
MY_DNS="DNS1="$4

Flag1=0
Flag2=0
Flag3=0
Flag4=0

if [ $# -lt 4 ];then
echo "Usage:./modif_ip.sh arg1[IPADDR] arg2[NETMASK] arg3[GATEWAY] arg4[DNS]."
exit 5
fi
if [ $# -gt 4 ];then
echo "Usage:./modif_ip.sh arg1[IPADDR] arg2[NETMASK] arg3[GATEWAY] arg4[DNS]."
exit 6
fi

cat /etc/sysconfig/network-scripts/ifcfg-eth0 | while read myline
do
if [[ "$myline" =~ "ONBOOT" ]];then
echo $MY_ONBOOT >> ifcfg-eth0
elif [[ "$myline" =~ "BOOTPROTO" ]];then
echo $MY_BOOTPROTO >> ifcfg-eth0
elif [[ "$myline" =~ "DEVICE" ]];then
echo $MY_DEVICE >> ifcfg-eth0
elif [[ "$myline" =~ "HWADDR" ]];then
echo $MY_HWADDR >> ifcfg-eth0
elif [[ "$myline" =~ "IPADDR" ]];then
Flag1=1
elif [[ "$myline" =~ "NETMASK" ]];then
Flag2=1
elif [[ "$myline" =~ "GATEWAY" ]];then
Flag3=1
elif [[ "$myline" =~ "DNS" ]];then
Flag4=1
else
echo $myline >> ifcfg-eth0
fi
done

if [ $Flag1 == 0 ];then
echo $MY_IPADDR >> ifcfg-eth0
fi

if [ $Flag2 == 0 ];then
echo $MY_NETMASK >> ifcfg-eth0
fi

if [ $Flag3 == 0 ];then
echo $MY_GATEWAY >> ifcfg-eth0
fi

if [ $Flag4 == 0 ];then
echo $MY_DNS >> ifcfg-eth0
fi

cp /root/ifcfg-eth0 /etc/sysconfig/network-scripts/
rm -rf /root/ifcfg-eth0