脚本名称：$0
PID：$$
参数个数：$#
脚本返回值：$?
第x个参数：$x
第10个以上的参数加大括号：${10}
所有参数：$@
#!/bin/bash
echo "The program $0 is now running"
echo "The progress PID is $$"
echo "The last progress PID is $$"
echo "The number of parameter is $# "
echo "The return code of last command is $?"
echo "The first parameter is $1"
echo "The second parameter is $2"
echo "The parameters are: $*"
echo "Again, the parameters are: $@"