shell脚本常用8例

基础的shell脚本实例

查看软件包有没有安装 #!/usr/bin/bash read -p "please input ruanjianbao " rj if rpm -q $rj &>/dev/null; then echo "$rj is already installed" else echo "$rj is not installed" fi

2.两个数比较大小

在这里插入代码片#!/usr/bin/bash read -p "please input the first num: " num1 read -p "please input the second num: " num2 if [[ $num1 =~ ^[0-9]+$ && $num2 =~ ^[0-9]+$ ]];then if [ $num1 -lt $num2 ];then echo "The num2 is biger than the num1" elif [ $num1 -eq $num2 ];then echo "Two number equal" else echo "The num1 is biger than the num2" fi else echo "please enter the correct number" fi unset num1 num2

3.乘法口诀表

#!/usr/bin/bash for i in {1..9};do for j in `seq 1 $i` ;do echo -en " $i * $j = $[ $i * $j ]\t" done echo done unset i j

4.求和

#!/usr/bin/bash for i in {1..9};do for j in `seq 1 $i` ;do echo -en " $i * $j = $[ $i * $j ]\t" done echo done unset i j

5.打印1-9

#!/usr/bin/bash num=0 while [ $num -lt 10 ] do echo $num let num=$num+1 done

6.字符判空

#!/usr/bin/bash num1=4 num2=5 str1=Alice str2=" " if [ $num1 -gt $num2 ] then echo num1 large than num2 else echo num1 lower than num2 fi if [ -z $str1 ] then echo str1 is empty else echo str is not empty fi if [ -z $str2 ] then echo str2 is empty else echo str is not empty fi

7.测试输入的文件类型

#!/usr/bin/bash read -p "input a file name:" file_name if [ -d $file_name ];then echo "$file_name is a directiory" elif [ -f $file_name ];then echo "$file_name is a file" elif [ -c $file_name ];then echo "$file_name is a devices" else echo "$file_name is unknown file" fi

8.自定义函数

#!/usr/bin/bash function func(){ echo this is function } func