通过 $? 来读取上一个命令执行的退出状态码

#!/bin/bash

# A snipet from a shell script ...
# Next we will invoke a command or another shell script

./myscript.sh

RETURN=$?

if [ $RETURN -eq 0 ];
then
  echo "The script myscript.sh was executed successfuly"
  exit 0
else
  echo "The script myscript.sh was NOT executed successfuly and returned the code $RETURN"
  exit $RETURN
fi