shell脚本1

数值累加
```shell
#!/bin/bash
read -p "please input a number: " num
s=0
for (( i=1;i<=$num;i++ ))
do
    s=$(( $s+$i ))
done
echo "the sum is : $s" 
```

---

字符串拼接
```shell
#!/bin/bash
# shell script

read -p "please input the firstname : " firstname
read -p "the lastname , please : " lastname

echo -e "\nthe name is : $firstname $lastname"
```

---

数值计算 (加,乘)
```shell
#!/bin/bash
# the compute numbers

read -p "input a number : " num
read -p "input another number : " num2
declare -i sum=$(($num+$num2))
echo -e "the sum of the two nums is $sum"
echo -e "the multiply of the two nums is $(( $num * $num2 ))"
```

---

测试参数1中的文件是否存在
```shell
#!/bin/bash

# test the file exist

test -e $1 && echo "exist !" || echo "not exist !"
```

---

if elif else 判定语句
```shell
#!/bin/bash

# the script show us how to if else

if [ "$1" == "hello" ]; then
        echo "Hello,how are you!"
elif [ "$1" == "" ]; then
        echo "You must input a param !"
else
        echo "The only legal param is 'hello'"
fi        
```

---

case判定 类似java switch 不过不需要用switch
```shell
#!/bin/bash

# the case judgement test
# case in esac
# the case judgement according to the case order

case $1 in
        "hello") # the param "hello"
                echo "hello,how are you! bro!?"
        ;;
        "") # the empty param
                echo "you must input a param like> {$0 param}"
        ;;
        1)
                echo "the number 1 is good"
        ;;
        2)
                echo "the number 2 is good"
        ;;
        3)
                echo "the number 3 is good"
        ;;
        *) # the wildcard
                echo "usage $0 {hello}"
        ;;
esac
```

---

启动和关闭redis

```shell
#!/bin/bash
# to quickly start redis

Resource_Name=/etc/init.d/redis
# first command symbol
cmd=$1

tpid=`ps -ef|grep $Resource_Name |grep -v grep|grep -v kill|awk '{print $2}'`

if [[ -z $cmd ]];then
    echo 'error,usage{ sh $0 1|0 to start or stop this redis}'
elif [[ $cmd -eq 1 ]];then
    $Resource_Name start
    echo $! > tpid
    echo 'Start Redis Success!~~~'
elif [[ $cmd -eq 0 ]];then
    echo '[test] Stop Redis Process'
    kill -15 $tpid
    sleep 5
    echo 'Kill Redis Processing!~~~'
    kill -9 $tpid
    echo 'Stop Redis Success!'
else
    echo 'error!just 1 or 0 behind $0, like (sh $0 1)'
fi
```

---

启动和关闭java的war包
```shell
#!/bin/bash
#by ukzqmooc

#time: 2019-10-22 14:40
#to quickly start the java war
resource_name=test20191024-8085.war

cmd=$1

tpid=`ps -ef|grep $resource_name|grep -v grep|grep -v kill|awk '{print $2}'`

#logic shell code follow
if [[ -z $cmd ]];then
        echo "err!usage{sh $0 1|0 to start or shutdown the test20191024-8085.war.}"
elif [[ $cmd -eq 1 ]];then
        nohup java -jar $resource_name > test20191024-8085.log 2>&1 &
elif [[ $cmd -eq 0 ]];then
        echo '<d83d><dc80> stop the war processing~'
        kill -15 $tpid
        sleep 5
        echo 'kill the war processing !'
        kill -9 $tpid
        echo 'stop the war success !'
else
        echo "err!just 1 or 0 behind $0,like(sh $0 1)"
fi
```