getopts命令中没有输入时如何回显

Question

This is put before the case statements. It still outputs nothing when executed without any input.

 while getopts :x:y:z: OPT; do
 if [ $OPT == "" ]; then
 echo "Null"
 exit 10
 fi

also, how should I code this to execute the values in any position/order? such as:

 .\project -x 120 -y 170 -z Car
 .\project -y 170 -z Car -x 120

Answer 1

You can first test if no arguments were passed at all and exit (this happens before the getopts loop):

if [ $# -eq 0 ]; then
  usage # Call usage function or echo some usage message
  exit 
fi

There's no way of forcing mandatory arguments. What you can do is test for a certain value after the getopts loop has finished.
If -x is a mandatory option, and it is used to set the var variable, test to see if it hasn't been set by the getopts loop, and if so print a relevant message and exit:

if [ -z ${var+x} ]; then
 echo "No -x argument supplied. exiting"
 exit 10
fi

The above runs after the case statement.

Also, you're missing a 'done' after your while loop, most likely a typo.