쉘스크립트 기본 if문

if문 - 

형식

if [ 조건문 ]

then 

실행명령1

elif [ 조건문 ]

then

실행명령2

else

실행명령3

fi  

-------------------

#!/bin/bash

man=100

woman=90

if [ "$man" -lt "$woman" ]

then

echo "여성이 더 많다"

elif [ "$man" -gt "$woman" ]

then

echo "남성이 더 많다"

else

echo "누가많던"

fi

-------------------

결과

# ./if1.sh 

남성이 더 많다

-----------------------

#!/bin/bash

if [ "-f.bashrc" ]

then

cp .bashrc .bashrc.old

echo "file copy ok"

elif [ "-f.bashrc.old" ]

then

echo "file ok"

else

echo "error"

fi

----------------------

# ./if2.sh 

file copy ok

해당디렉토리에 .bashrc파일이있으면 .bashrc.old 로 카피한다

----------------------

#!/bin/bash

ME="cdral"

YOU="who"

if [ "$1" = "$ME" ]

then

echo "hi cdral"

elif [ "$1" = "$YOU" ]

then

echo "who are you?"

fi

---------------------

# ./if3.sh cdral

hi cdral

# ./if3.sh who

who are you?

-----------------------

#!/bin/bash

echo Who are you?

read tomjerry

if [ "$tomjerry" = "tom" ];

then

echo hi

elif [ "$tomjerry" = "jerry" ];

then

echo hello

else

echo bye

fi

----------------------

결과

# ./if.sh 

Who are you?

tom

hi

# ./if.sh 

Who are you?

jerry

hello

# ./if.sh 

Who are you?

can

bye