Shell if...elif...fi 語句

#!/bin/sh

a=10

b=20

if [ $a == $b ]

then

   echo "a is equal to b"

elif [ $a -gt $b ]

then

   echo "a is greater than b"

elif [ $a -lt $b ]

then

   echo "a is less than b"

else

   echo "None of the condition met"

fi