关于空格

在shell中空格永不好很容易出错误，例如

#!/bin/sh


echo "Is moring?Pleash answer yes or no"

while [ "$aser" != "ok" ]
do
read  timeofday
aser="ok"
##赋值的地方不用空格
echo "aser = $aser"
##判断的地方必须要用空格
case "$timeofday" in
yes) echo "Good Morning";;
no)  echo "Good Afternoon";;
y)  echo "Good Morning";;
n)  echo "Good Afternoon";;
*) aser="wait"
echo "aser now = $aser"
echo "Sorry,answer not recognized";;
esac
echo "Tests $aser $timeofday"
done
echo "Good Bye"
exit 0