shell脚本编程学习笔记-shell数组

Posted 2020-10-31

1.数组的介绍

平时定义a=1;b=2;c=3，变量多了，再一个一个定义就费劲了。

简单的说数组就是数据类型的元素按一定顺序排列的集合。

数组就是有限个元素变量或数据用一个名字命名，然后用编号区分他们的变量的集合，这个名字称为数组，编号称为数组的下标。组成数组的多个变量称为数组的分量，也称为数组的元素，有时也称为下标变量。

2.数组的定义与增删改查

(1) 数组的定义

一对括号表示数组，数组元素用“空格”符号分隔开

array=(value1 value2 value3….)

[[email protected] ~]# array=(1 2 3)

(2) 获取数组的长度

[[email protected] ~]# echo ${#array[*]}
3
[[email protected] ~]# echo ${#array[@]}
3

(3) 打印数组元素

[[email protected] ~]# echo ${array[0]}
1
[[email protected] ~]# echo ${array[1]}
2
[[email protected] ~]# echo ${array[2]}
3
[[email protected] ~]# echo ${array[*]}
1 2 3

(4) for循环打印数组

方法一：

[[email protected] 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

[[email protected] jiaobenlianxi]# sh array01.sh 
192.168.1.111
192.168.1.112
192.168.1.113

方法二：用C语言方式

[[email protected] 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
[[email protected] jiaobenlianxi]# sh array02.sh 
192.168.1.114
192.168.1.115
192.168.1.116

(5) 数组的增加

[[email protected] jiaobenlianxi]# array=(1 2 3)
[[email protected] jiaobenlianxi]# echo ${array[*]}
1 2 3
[[email protected] jiaobenlianxi]# array[3]=4
[[email protected] jiaobenlianxi]# echo ${array[*]}
1 2 3 4

(6) 删除数组

[[email protected] jiaobenlianxi]# unset array[0]
[[email protected] jiaobenlianxi]# echo ${array[*]}
2 3 4

(7) 数组内容的截取和替换（和变量子串的替换很像）

截取：

[[email protected] jiaobenlianxi]# array=(1 2 3 4 5)
[[email protected] jiaobenlianxi]# echo ${array[*]:1:3}
2 3 4
[[email protected] jiaobenlianxi]# echo ${array[*]:3:4}
4 5

替换：

[[email protected] jiaobenlianxi]# echo ${array[*]/3/4} 把数组中的3替换成4临时替换，原数组未做改变
1 2 4 4 5
[[email protected] jiaobenlianxi]# array1=(${array[*]/3/4})
[[email protected] jiaobenlianxi]# echo ${array1[*]}
1 2 4 4 5

3.命令结果定义数组

[[email protected] jiaobenlianxi]# array=($(ls))
[[email protected] jiaobenlianxi]# echo ${array[1]}
1.sh
[[email protected] jiaobenlianxi]# echo ${array[2]}
a.log
[[email protected] jiaobenlianxi]# echo ${array[3]}
array01.sh
[[email protected] 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
[[email protected] jiaobenlianxi]# cat array03.sh
array=(
    $(ls)
)

for((i=0;i<${#array[*]};i++))

do
    echo ${array[i]}
done

4.Shell数组知识小结

（1）定义：

静态数组：array=(1 2 3) 空格隔开

动态数组：array=($(ls))

给数组赋值：array[3]=4

（2）打印

打印所有元素：${array[*]}或${array[@]}

打印数组长度：${#array[@]}或${#array[*]}

打印单个元素：${array[i]} i是数组下标