用bash来计算子网掩码

工作需要， 在cu上搜到的一个解法， “网中人”写的， 很牛：

 

#!/bin/bash                                           
                                                      
#ip=$(cat "$@" | awk 'BEGIN{ FS="/" }{ print $1 }')
kk=$(cat "$@")
all=(${kk//[!0-9]/ })                                  
[ "${#all[@]}" != "8" ] && {                          
        echo "Usage: "                                
        echo "${0##*/} ip.ip.ip.ip/mask.mask.mask.mask"
        exit 1                                        
}                                                     
                                                      
get_addr () {                                         
        if [ "$1" = "-b" ]; then                      
                op='|'; op1='^'; arg='255'            
                shift                                 
        else                                          
                op='&'                                
        fi                                            
        unset address                                 
        while [ "$5" ]; do                            
                num=$(( $1 $op ($5 $op1 $arg) ))       # 广播地址的算法： 掩码先按位取反， 然后跟ip做位或操作， 这里跟位1作异或操作跟位反操作等价
                shift                                 
                address="$address.$num"               
        done                                          
}                                                     
                                                      
get_addr ${all[@]}                                    
network="${address#.}"
get_addr -b ${all[@]}                                 
broadcast="${address#.}"
echo "$network $broadcast"

 

 

这个是awk版的：
##!/bin/bash

# G_network () {
# echo $@ | awk 'BEGIN{FS="[./]";OFS="."}
#     END{
#         print and($1,$5),and($2,$6),and($3,$7),and($4,$8)
#     }'
# }
#
# G_broadcast () {
# echo $@ | awk 'BEGIN{FS="[./]";OFS="."}
#     END{
#         print or($1,xor($5,255)),or($2,xor($6,255)),or($3,xor($7,255)),or($4,xor($8,255))
#     }'
# }
#
# ###
# # main
# ###
# ALL_IP=192.168.23.32/255.255.252.0
# G_network $ALL_IP
# G_broadcast $ALL_IP

 

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