Ubuntu中文论坛

我的代码是：
#!/bin/bash
#This program is used to study if then
#user 2009/12/14
if [ "$1" = "hello" ]; then
echo "Hello! How are you ?"
elif [ "$1" = " " ]; then
echo "You MUST input parameters"
else
echo "The only accept parameter is hello"
fi

elif [ "$1" = " " ]; then
echo "You MUST input parameters" 这两行代码始终不执行，请问是什么原因阿?谢谢

你的" "之间貌似有空格

非常感谢！！已经可以正常运行了。我买的这本书上有很多错误，太烦了！