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