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…。

1 #!/bin/bash
2 #
3 printf "The complete list is %s\n" "$$"
4 printf "The complete list is %s\n" "$!"
5 printf "The complete list is %s\n" "$?"
6 printf "The complete list is %s\n" "$*"
7 printf "The complete list is %s\n" "$@"
8 printf "The complete list is %s\n" "$#"
9 printf "The complete list is %s\n" "$0"
10 printf "The complete list is %s\n" "$1"
11 printf "The complete list is %s\n" "$2
结果：

[Aric@localhost ~]$ bash params.sh 123456 QQ
The complete list is 24249
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 params.sh
The complete list is 123456
The complete list is QQ