linux中shell变量$#,$@,$0,$1,$2的含义解释:
变量说明:
$$
Shell本身的PID(ProcessID)
$!
Shell最后运行的后台Process的PID
$?
最后运行的命令的结束代码(返回值)
$-
使用Set命令设定的Flag一览
$*
所有参数列表。如"$*"用「"」括起来的情况、以"$1 $2 … $n"的形式输出所有参数。
$@
所有参数列表。如"$@"用「"」括起来的情况、以"$1" "$2" … "$n" 的形式输出所有参数。
$#
添加到Shell的参数个数
$0
Shell本身的文件名
$1~$n
添加到Shell的各参数值。$1是第1参数、$2是第2参数…。
示例:
1 #!/bin/bash
2 #
3 printf "The complete list is %s
" "$$"
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
Have a nice day!!!