linux中shell变量$#,$@,$0,$1,$2的含义解释

linux中shell变量$#,$@,$0,$1,$2的含义解释: 

变量说明: 

$$ 

Shell本身的PID（ProcessID） 

$! 

Shell最后运行的后台Process的PID 

$? 

最后运行的命令的结束代码（返回值） 

$- 

使用Set命令设定的Flag一览 

$* 

所有参数列表。如"$*"用「"」括起来的情况、以"$1 $2 … $n"的形式输出所有参数。 

$@ 

所有参数列表。如"$@"用「"」括起来的情况、以"$1" "$2" … "$n" 的形式输出所有参数。 

$# 

添加到Shell的参数个数 

$0 

Shell本身的文件名 

$1～$n 
添加到Shell的各参数值。$1是第1参数、$2是第2参数…。

#!/bin/bash
printf "The complete list is %s\n" "$$"
printf "The complete list is %s\n" "$!"
printf "The complete list is %s\n" "$?"
printf "The complete list is %s\n" "$*"
printf "The complete list is %s\n" "$@"
printf "The complete list is %s\n" "$#"
printf "The complete list is %s\n" "$0"
printf "The complete list is %s\n" "$1"
printf "The complete list is %s\n" "$2"
结果：

/bin/bash exe.sh 123456 QQ

The complete list is 16558
The complete list is
The complete list is 0
The complete list is 123456 QQ
The complete list is 123456
The complete list is QQ
The complete list is 2
The complete list is exe.sh
The complete list is 123456
The complete list is QQ