Linux bianliang

Linux中变量#,

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…。

示例：

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

Have a nice day!!!