網絡地址計算（Linux版）

1. #!/bin/bash
2. #History:
3. # 2012-02-20 DanielW|Kernel First release
4. #
5. PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin export PATH
7. #二進制轉十進制
8. function multiply_2(){
9. declare -i n
10. n=$1
12. multiply_result=1
13. while [ $n -gt 0 ]
14. do
15. multiply_result=$(( $multiply_result*2 ))
16. n=$n-1
17. done
18. export multiply_result
19. }
21. ##十進制轉二進制，得出ip和mask的某一段的二進制
22. function cal(){
23. declare -i a
24. declare -i b
25. declare -i len
26. a=$1
27. b=$2
28. m=""
29. n=""
31. m=$(( a%2 ))
32. while [ $(( a/2 )) -gt 0 ]
33. do
34. a=$(( a/2 ))
35. m=$((a%2))$m
36. done
37. len=8-$( expr length $m )
38. while [ $len -gt 0 ]
39. do
40. m=0$m
41. len=$(( len-1 ))
42. done
43. n=$(( b%2 ))
44. while [ $(( b/2 )) -gt 0 ]
45. do
46. b=$(( b/2 ))
47. n=$((b%2))$n
48. done
49. len=8-$(expr length $n)
50. while [ $len -gt 0 ]
51. do
52. n=0$n
53. len=$(( len-1 ))
54. done
55. export m
56. export n
57. }
59. #做與運算，並輸出十進制
60. function ip_and_mask(){
61. declare -i int
62. ten=""
63. ip="0"
64. int=8
65. a=""
66. b=""
67. result=""
68. while [ $int -gt 0 ]
69. do
70. a=$( expr substr $1 $int 1 )
71. b=$( expr substr $2 $int 1 )
72. if [ "$a" == "1" -a "$b" == "1" ];then
73. result=1${result}
74. else result=0${result}
75. fi
76. int=$int-1
77. done
79. if [ "$( expr substr $result 8 1 )" == "1" ];then
80. ip=1
81. else ip=0
82. fi
83. int=7
84. while [ $int -ge 0 ]
85. do
86. if [ "$( expr substr $result $int 1 )" == "1" ];then
87. tmp_n=$(( 8-int ))
88. ip=$(( ip+$( multiply_2 $tmp_n ) ))
89. fi
90. int=$int-1
91. done
92. export ip
93. }
95. read -p "Enter the IP Address:" ip_input
96. read -p "Enter the NETMASK Address:" mask
97. declare -i M1=$( echo $mask | awk 'BEGIN{FS="."}{print $1}' )
98. declare -i M2=$( echo $mask | awk 'BEGIN{FS="."}{print $2}' )
99. declare -i M3=$( echo $mask | awk 'BEGIN{FS="."}{print $3}' )
100. declare -i M4=$( echo $mask | awk 'BEGIN{FS="."}{print $4}' )
101. declare -i P1=$( echo $ip_input | awk 'BEGIN{FS="."}{print $1}' )
102. declare -i P2=$( echo $ip_input | awk 'BEGIN{FS="."}{print $2}' )
103. declare -i P3=$( echo $ip_input | awk 'BEGIN{FS="."}{print $3}' )
104. declare -i P4=$( echo $ip_input | awk 'BEGIN{FS="."}{print $4}' )
105. if [ $M1 -ne 255 ];then
106. cal $M1 $P1
107. ip_and_mask $m $n
108. echo -e "Net Address:"$ip.0.0.0
109. elif [ $M2 -ne 255 ];then
110. cal $M2 $P2
111. ip_and_mask $m $n
112. echo "Net Address:"$P1.$ip.0.0
113. elif [ $M3 -ne 255 ];then
114. cal $M3 $P3
115. ip_and_mask $m $n
116. echo "Net Address:"$P1.$P2.$ip.0
117. else [ $M4 -ne 255 ]
118. cal $M4 $P4
119. ip_and_mask $m $n
120. echo "Net Address:"$P1.$P2.$P3.$ip
121. fi
122. echo "END"

這個版本還沒有對輸入的數據進行判斷，而且沒有使用位運算（原來不會啊），導致了代碼過長過復雜，等待下個版本更新。

這裡還有一個可以自動獲取主機網絡地址判斷的腳本 http://www.linuxidc.com/Linux/2012-02/55060p2.htm