Linux 명령어(쉘 프로그래밍) - 예제(숫자 Integer 계산, Shell로 인자 넘기기)

1) test.sh (pringout time and date & who logged on the server)

 

#! /bin/bash
#Test Shell Program

#pringout time and date
echo time and date :
date

#who logged on the server
echo who logged on the server :
who

 

 

 

 

 

 

 

2) test2.sh (Test how to use environment variables)

 

#!/bin/bash
#Test how to use environment variables

echo Display user information
echo user id : $USER
echo UID : $UID
echo HOME : $HOME

 

 

 

 

 

3) test3.sh (숫자 계산)

 

#!/bin/bash
num1=10
num2=20
num3=30
r_add=$(expr $num1 + $num2 + $num3)
r_sub=$(expr $num2 - $num1)
r_mul=$(expr $num1 \* $num2)
r_div=$(expr $num2 / $num1)
echo $r_add
echo $r_sub
echo $r_mul
echo $r_div

 

 

 

 

 

4) test4.sh (숫자 계산)

 

#!/bin/bash

num1=10
num2=20
num3=30

r_add=$[$num1 + $num2 + $num3]
r_sub=$[$num2 - $num1]
r_mul=$[$num1 * $num2]
r_div=$[$num2 / $num1]

echo $r_add
echo $r_sub
echo $r_mul
echo $r_div

 

 

 

5) shell파일에 인자 넘기기

#!/bin/bash

add=$[$1 + $2]
sub=$[$1 - $2]
mul=$[$1 * $2]
div=$[$1 / $2]

echo add : $add sub : $sub mul : $mul div : $div

=> 실행 :

. test6.sh 3 5