linux中shell變量$#,$@,$0,$1,$2的含義解釋:
變量說明:
$$
Shell本身的PID(ProcessID)
$!
Shell最後運行的後臺Process的PID
$?
最後運行的命令的結束代碼(返回值)
$-
使用Set命令設定的Flag一覽
$*
所有參數列表。如"$*"用「"」括起來的情況、以"$1 $2 … $n"的形式輸出所有參數。
$@
所有參數列表。如"$@"用「"」括起來的情況、以"$1" "$2" … "$n" 的形式輸出所有參數。
$#
添加到Shell的參數個數
$0
Shell本身的文件名
$1~$n
添加到Shell的各參數值。$1是第1參數、$2是第2參數…。
示例:
1 #!/bin/bash
2 #
3 printf "The complete list is %s\n" "$$"
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" "$2 |
結果:
[Aric@localhost ~]$ 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 |