shell腳本編程學習筆記-shell數組
阿新 • • 發佈:2018-04-15
shell linux 1.數組的介紹
平時定義a=1;b=2;c=3,變量多了,再一個一個定義就費勁了。
簡單的說數組就是數據類型的元素按一定順序排列的集合。
數組就是有限個元素變量或數據用一個名字命名,然後用編號區分他們的變量的集合,這個名字稱為數組,編號稱為數組的下標。組成數組的多個變量稱為數組的分量,也稱為數組的元素,有時也稱為下標變量。
2.數組的定義與增刪改查
(1) 數組的定義
一對括號表示數組,數組元素用“空格”符號分隔開
array=(value1 value2 value3….)
[root@shellbiancheng ~]# array=(1 2 3)
(2) 獲取數組的長度
[root@shellbiancheng ~]# echo ${#array[*]} 3 [root@shellbiancheng ~]# echo ${#array[@]} 3
(3) 打印數組元素
[root@shellbiancheng ~]# echo ${array[0]}
1
[root@shellbiancheng ~]# echo ${array[1]}
2
[root@shellbiancheng ~]# echo ${array[2]}
3
[root@shellbiancheng ~]# echo ${array[*]}
1 2 3
(4) for循環打印數組
方法一:
[root@shellbiancheng jiaobenlianxi]# cat array01.sh array=( 192.168.1.111 192.168.1.112 192.168.1.113 ) for ip in ${array[*]} do echo $ip sleep 2 done [root@shellbiancheng jiaobenlianxi]# sh array01.sh 192.168.1.111 192.168.1.112 192.168.1.113
方法二:用C語言方式
[root@shellbiancheng jiaobenlianxi]# cat array02.sh
array=(
192.168.1.114
192.168.1.115
192.168.1.116
)
for((i=0;i<${#array[*]};i++))
do
echo ${array[i]}
sleep 2
done
[root@shellbiancheng jiaobenlianxi]# sh array02.sh
192.168.1.114
192.168.1.115
192.168.1.116
(5) 數組的增加
[root@shellbiancheng jiaobenlianxi]# array=(1 2 3)
[root@shellbiancheng jiaobenlianxi]# echo ${array[*]}
1 2 3
[root@shellbiancheng jiaobenlianxi]# array[3]=4
[root@shellbiancheng jiaobenlianxi]# echo ${array[*]}
1 2 3 4
(6) 刪除數組
[root@shellbiancheng jiaobenlianxi]# unset array[0]
[root@shellbiancheng jiaobenlianxi]# echo ${array[*]}
2 3 4
(7) 數組內容的截取和替換(和變量子串的替換很像)
截取:
[root@shellbiancheng jiaobenlianxi]# array=(1 2 3 4 5)
[root@shellbiancheng jiaobenlianxi]# echo ${array[*]:1:3}
2 3 4
[root@shellbiancheng jiaobenlianxi]# echo ${array[*]:3:4}
4 5
替換:
[root@shellbiancheng jiaobenlianxi]# echo ${array[*]/3/4} 把數組中的3替換成4臨時替換,原數組未做改變
1 2 4 4 5
[root@shellbiancheng jiaobenlianxi]# array1=(${array[*]/3/4})
[root@shellbiancheng jiaobenlianxi]# echo ${array1[*]}
1 2 4 4 5
3.命令結果定義數組
[root@shellbiancheng jiaobenlianxi]# array=($(ls))
[root@shellbiancheng jiaobenlianxi]# echo ${array[1]}
1.sh
[root@shellbiancheng jiaobenlianxi]# echo ${array[2]}
a.log
[root@shellbiancheng jiaobenlianxi]# echo ${array[3]}
array01.sh
[root@shellbiancheng jiaobenlianxi]# echo ${array[*]}
1-100.sh 1.sh a.log array01.sh array02.sh beijingcolor.sh b.log break.sh case01.sh check.sh chkconfigoff.sh chkconfigon.sh color1.sh color.sh for1-1000.sh for1-100_3.sh for1-100.sh for1.sh for2.sh for3.sh for4.sh for5.sh hanshu01.sh hanshu02.sh huafei.sh menufruit.sh nginx.sh piliangxiugai1.sh piliangxiugai2.sh piliangxiugai3.sh suijiwnjian.sh sum1-100.sh test uptime.sh usage.sh user.sh while1.sh while2.sh while3.sh while4.sh while.sh zhuajiu.sh
[root@shellbiancheng jiaobenlianxi]# cat array03.sh
array=(
$(ls)
)
for((i=0;i<${#array[*]};i++))
do
echo ${array[i]}
done
4.Shell數組知識小結
(1)定義:
靜態數組:array=(1 2 3) 空格隔開
動態數組:array=($(ls))
給數組賦值:array[3]=4
(2)打印
打印所有元素:${array[*]}或${array[@]}
打印數組長度:${#array[@]}或${#array[*]}
打印單個元素:${array[i]} i是數組下標
shell腳本編程學習筆記-shell數組