Shell-basic practice script (a must-see for novices)

1. Basic practice script questions

1. Exercise one

Check whether the test.sh file in the user's home directory exists, and check whether it has execute permission.

#!/bin/bash

if [ -f test.sh ];then
 echo "test.sh文件存在"

  if [ -x test.sh ];then
    echo "test.sh文件有执行权限"
  else
    echo "tset.sh文件没有权限"
  fi

else
 echo "tset.sh不存在"

fi

2. Exercise 2

Prompt the user to enter the number of seconds for the 100-meter race. It is required to determine whether the number of seconds is greater than 0 and less than or equal to 10 seconds to enter the trial. Those greater than 10 seconds are eliminated. If other characters are entered, they will be prompted to re-enter; the members who enter the trial will further judge the gender of men and women. , Boys enter the boys group, and girls enter the girls group. If you make a mistake, please indicate an error.

#!/bin/bash
read -p "输入100米赛跑秒数(1-100):" a

if [[ $a -gt 0 && $a -le 10 ]] &> /dev/null ;then
  echo '您以成功晋级选拔赛'

read -p "请输入你的性别(男/女):" b

  if [ $b = 男 ];then
    echo "您已进入男子组"
  elif [ $b = 女 ];then
    echo "您已进入女子组"
  else
    echo "请正确输入"
  fi

elif [ $a -gt 10 ] &> /dev/null ;then
  echo "您已被淘汰"
else
  echo "请正确输入"
fi

3. Exercise three

Use the case statement to decompress the compressed package with the suffix .tar.gz or .tar.bz2 to the /opt directory.

#!/bin/bash

case $1 in
*.tar.gz)
  if [ -f $1 ];then
    tar -zxvf $1 -C /opt &> /dev/null
  else
    echo "$1 不存在"
  fi
;;

*.tar.bz2)
  if [ -f $1 ];then
   tar -jxvf $1 -C /opt &> /dev/null
  else
   echo "$1 不存在"
  fi
;;

*)
  echo "文件输入错误" 
esac

4. Exercise four

Prompt the user to input content, use the if statement to determine whether the input content is an integer.

#!/bin/bash#整数
read -p "请输入数字:" a

if [ $a = 0 ];then
 echo "0 是整数"
else

  let i=a+0 &> /dev/null
  if [ $? = 0 ];then
    echo " $a 是整数"
  else
   echo " $a 不是整数"
  fi
  
fi                                                                                                                          

5. Exercise five

According to the previous question, judge whether the input is odd or even.

#!/bin/bash

read -p "请输入数字:" a

if [ $a = 0 ];then
 echo " 0 是整数也是偶数"

else
let i=a+0 &> /dev/null

  if [ $? = 1 ];then
  echo " $a 不是整数也不是奇偶数"
  else
     let b=a%2 &> /dev/null

     if [ $? = 1 ];then
       echo " $a 是整数是偶数"
     else
       echo " $a 是整数是奇数"
     fi
  fi
fi