shell指令碼編程學習筆記-shell數組

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1.數組的介紹

平時定義a=1;b=2;c=3，變數多了，再一個一個定義就費勁了。

簡單的說數組就是資料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數或資料用一個名字命名，然後用編號區分他們的變數的集合，這個名字稱為數組，編號稱為數組的下標。組成數組的多個變數稱為數組的分量，也稱為數組的元素，有時也稱為下標變數。

2.數組的定義與增刪改查

(1) 數組的定義

一對括弧表示數組，數組元素用“空格”符號分隔開

array=(value1 value2 value3….)

[[email protected] ~]# array=(1 2 3)

(2) 擷取數組的長度

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

(3) 列印數組元素

[[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迴圈列印數組

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 2done[[email protected] jiaobenlianxi]# sh array01.sh 192.168.1.111192.168.1.112192.168.1.113

方法二：用C語言方式

[[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 2done[[email protected] jiaobenlianxi]# sh array02.sh 192.168.1.114192.168.1.115192.168.1.116

(5) 數組的增加

[[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) 刪除數組

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

(7) 數組內容的截取和替換（和變數子串的替換很像）

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

替換：

[[email protected] jiaobenlianxi]# echo ${array[*]/3/4} 把數組中的3替換成4臨時替換，原數組未做改變1 2 4 4 5[[email protected] jiaobenlianxi]# array1=(${array[*]/3/4})[[email protected] jiaobenlianxi]# echo ${array1[*]}1 2 4 4 5

3.命令結果定義數組

[[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.sharray=(    $(ls))for((i=0;i<${#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）列印

列印所有元素：${array[*]}或${array[@]}

列印數組長度：${#array[@]}或${#array[*]}

列印單個元素：${array[i]} i是數組下標

shell指令碼編程學習筆記-shell數組