如何使用if elif和else使用bash进行多项选择

if [ condition ]; then
    # code block executed when the condition is true
fi

if [ condition1 ]; then
    # code block executed when condition1 is true
elif [ condition2 ]; then
    # code block executed when condition2 is true
elif [ condition3 ]; then
    # code block executed when condition3 is true
else
    # code block executed when all conditions are false
fi

#!/bin/bash

read -p "Enter a number: " num

if [ $num -eq 0 ]; then
    echo "The number is zero."
elif [ $num -gt 0 ]; then
    echo "The number is positive."
else
    echo "The number is negative."
fi