公司的無線環境采用mac地址認證的方式，mac地址被綁定到Radius的users配置文件中，將注冊了的mac地址作為用戶名和密碼。為了方便的管理這些mac地址，自己寫了一個shell腳本來管理。

shell腳本所特有的強大文本處理能力和各種命令函數的組合，使得管理員的工作能輕松不少。

下面就列出該腳本的功能以示參考：

• 添加mac地址
• 刪除mac地址
• 查找mac地址
• 去除重復mac地址
• 檢查mac地址合法性
• TODO，導入導出mac地址，添加注釋
</ul>

其中用到的Shell腳本技術包括但不限于：

• 文本文件的列處理和行處理，如sed、awk等命令
• 字符串查找、過濾、大小寫轉換，bash和grep等命令
• 獲取、計算、比較字符串長度，bash和wc等命令
• mac地址正則表達式的處理和類型轉換
• shell編程操作、包括文件包含、函數、參數傳遞、返回值等
• 其他
</ul>

代碼示例：

#!/bin/bash
#

Source function library.
. /etc/rc.d/init.d/functions
RADIUSD=/usr/sbin/radiusd
LOCKF=/var/lock/subsys/radiusd
CONFIG=/etc/raddb/radiusd.conf
USERCONFIG=/etc/raddb/users
[ -f $RADIUSD ] || exit 0
[ -f $CONFIG ] || exit 0
[ -f $USERCONFIG ] || exit 0
RETVAL=0
OPERATION=$1
MACADDRESS=$2
function help()
{
    clear
    echo $""
    echo $"===================================================================================="
    echo $"For Radius on Fedora/CentOS/RadHat Linux Server, Written by Chris"
    echo $"===================================================================================="
    echo $"A tool to manage Radius server"
    echo $""
    echo $"Usage: $0 {find|add|modify|delete|check|remove|start|stop|status|restart|reload} mac"

#TODO
echo $"Usage: $0 {import|export|debug}"
echo $""
echo $"For more information please contract dgdenterprise@gmail.com"
echo $"===================================================================================="
echo $""
exit 1

}
function mac()
{
    if [ -z $MACADDRESS ];then
        echo $"no mac address is signed! "
        echo $"\$2 is $MACADDRESS"
        exit 1
    else
                if [[ "${#MACADDRESS}" != "12" ]] && [[ "${#MACADDRESS}" != "17" ]] ;then
            echo "mac length is ${#MACADDRESS}"
                        echo "mac address is illegal! "
            exit 1
else
echo $"mac which you input is $MACADDRESS"

            fi
    #echo $MACADDRESS | sed -nr '/[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}/p'
    #echo $MACADDRESS | sed -nr '/[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}/p'
    #echo $MACADDRESS | sed -nr '/[A-Fa-f0-9]{12}/p'
    if [[ `echo $MACADDRESS | grep -` ]];then
        PROMAC=`echo $MACADDRESS | sed -nr '/[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}-[A-Fa-f0-9]{2}/p' | tr '[:upper:]' '[:lower:]' | sed 's/-//g'`
    elif [[ `echo $MACADDRESS | grep :` ]];then
        PROMAC=`echo $MACADDRESS | sed -nr '/[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}/p' | tr '[:upper:]' '[:lower:]' | sed 's/://g'`
    else
        PROMAC=`echo $MACADDRESS | tr '[:upper:]' '[:lower:]'`
    fi
    echo $PROMAC
fi

}
function find()
{
    MAC=mac
    echo $"accepted mac is $MAC"
    if [[ grep $MAC $USERCONFIG ]]; then
        MACLINE=grep -n $MAC $USERCONFIG | awk -F ':' '{print $1}'

    #echo $MACLINE
    MACLINECOUNT=$(echo $MACLINE | wc -w)
    #echo $MACLINECOUNT
    if [[ "$MACLINECOUNT" != "1" ]];then
        echo $"ERROR, this mac $MAC has duplicate record, you should use $0 remove $MAC to remove duplicate record"
        exit 1
    fi
    echo $"Successfully find $MAC in $MACLINE line of file $USERCONFIG! "
    echo
    REVAL=$?
else
    echo $"Can not find $MAC in file $USERCONFIG! "
    echo
    exit 1
    REVAL=$?
fi

}
function add()
{
    MAC=mac
    echo $"accepted mac is $MAC"

#find $MAC
LINENUM=`grep -n "Cleartext-Password :='" users | grep -v \# | head -n1 | awk -F ":" '{print $1}'`
SEDOPERATION=$LINENUM"a"
sed -i "$SEDOPERATION $MAC    Cleartext-Password :='$MAC'" $USERCONFIG
find $MAC
restart

}
function modify()
{
    MAC=mac
    find $MAC

#TODO


}
function delete()
{
        MAC=mac
        echo $"accepted mac is $MAC"
        if [[ grep $MAC $USERCONFIG ]]; then
                MACLINE=grep -n $MAC $USERCONFIG | awk -F ':' '{print $1}'

            ##echo $MACLINE
            #MACLINECOUNT=$(echo $MACLINE | wc -w)
            ##echo $MACLINECOUNT
            #if [[ "$MACLINECOUNT" != "1" ]];then
            #        echo $"ERROR, this mac $MAC has duplicate record, you should use $0 remove $MAC to remove duplicate record"
            #        exit 1
            #fi
            echo $"Successfully find $MAC in $MACLINE line of file $USERCONFIG! "
    echo $"It will be deleted! "
    sed -i "$MACLINE d" $USERCONFIG
    #TODO
    echo $"If you see 'Can not find $MAC in file $USERCONFIG! ', it means successfully! "
    find $MAC
            echo
            REVAL=$?
    else
            echo $"Can not find $MAC in file $USERCONFIG! "
            echo
            REVAL=$?
    fi

}
function check()
{
    MAC=mac
    find $MAC
    remove $MAC
}
function remove()
{
    MAC=mac
        echo $"accepted mac is $MAC"

#TODO
#echo $"backuped file to file $FILENAME"
    if [[ `grep $MAC $USERCONFIG` ]]; then
            MACLINE=`grep -n $MAC $USERCONFIG | awk -F ':' '{print $1}'`
            #echo $MACLINE
            MACLINECOUNT=$(echo $MACLINE | wc -w)
            #echo $MACLINECOUNT
            if [[ "$MACLINECOUNT" == "1" ]];then
                    echo $"WARNNING, this mac $MAC is good record, no duplicate record has found! "
                    exit 0
            fi
TOREMOVE="$MAC    Cleartext-Password :='$MAC'"
sed -i "/^$TOREMOVE$/d" $USERCONFIG
add $MAC
fi

}
function restart()
{
    service radiusd restart
}
function reload()
{
    service radiusd reload
}
function status()
{
    service radiusd status
}
case "$1" in 
    find)
        find
        RETVAL=$?
    ;;
    add)
        add
        RETVAL=$?
    ;;
    modify)
        modify
        RETVAL=$?
    ;;
    delete)
        delete
        RETVAL=$?
    ;;
    check)
        check
        RETVAL=$?
    ;;
    remove)
        remove
        RETVAL=$?
    ;;
    start)
        start
        RETVAL=$?
    ;;
    stop)
        stop
        RETVAL=$?
    ;;
    status)
        status
        RETVAL=$?
    ;;
    restart)
        restart
        RETVAL=$?
    ;;
    reload)
        reload
        RETVAL=$?
    ;;
    *)
        help
        exit 1
    ;;
esac</pre>原文來自：urey_pp 的BLOG