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：

#/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"  $@
printf "The complete list is %s\n" "$#"
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：

[root@bogon bin]# bash ceshi.sh 123456 QQ
The complete list is 14739
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 123456
The complete list is QQ
The complete list Is 123456
The complete list Is QQ
The complete list is 2
The complete list is ceshi.sh
The complete list is 123456
The complete list is QQ

摘抄自：ABS_GUIDE

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