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[Shell Script] 조건문 if 문법(bash_if)

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조건문 if 문법

기본 구문(if문)

if [ expression ]

then

    statement

fi

활용 예제

#!/bin/bash

a=10
b=20

if [ $a = 10 ] && [ $b = 20 ]
then
    echo "a is 10 and b is 20"
fi
$ bash example.sh
a is 10 and b is 20

if - else 문

if [ expression ]

then

    statement

else

    statement

fi

활용 예제

#!/bin/bash

a=10
b=20

if ! [ $a = $b ]
then
    echo "a is not equal to b"
else
    echo "a is equal to b"
fi
$ bash example.sh
a is not equal to b

if - elif - else 문

if [ expression ]

then

    statement

elif [ expression ]

then

    statement

else

    statement

fi

활용 예제

#!/bin/bash

a=10
b=20

if [ $a = $b ]
then
    echo "a is equal to b"
elif [ $a -lt $b ]
then
    echo "a is less than b"
else
    echo "a is not equal to b"
fi
$ bash example.sh
a is less than b

 

참고URL

- Bash Shell - 조건문(if-else) : https://codechacha.com/ko/shell-script-if-else/

 

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