echo "上一次后台pid is $!"
echo "当前进程pid is $$"
echo "last command return code is :$?"
echo "bash file name is $0"
echo "all var is: $*"
echo "var number is : $# "
===========gold line of out=========
上一次后台pid is
当前进程pid is 53971
last command return code is :0
bash file name is echo_var.sh
all var is: 1 44 test this
var number is : 4
获取脚本name和脚本目录：
basename filepath
dirname filepath