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:

• $$

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
" "$$"
 4 printf "The complete list is %s
" "$!"
 5 printf "The complete list is %s
" "$?"
 6 printf "The complete list is %s
" "$*"
 7 printf "The complete list is %s
" "$@"
 8 printf "The complete list is %s
" "$#"
 9 printf "The complete list is %s
" "$0"
10 printf "The complete list is %s
" "$1"
11 printf "The complete list is %s
" "$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

参考：

http://www.cnblogs.com/fhefh/archive/2011/04/15/2017613.html

http://www.tldp.org/LDP/abs/abs-guide.pdf