Linux in shell variable $#,$@,$0,$1,$2 meaning explanation:

Variable Description:

$$        Shell自己PID（ProcessID） $!         Shell背景上次执行Process的PID $?         命令的结束代码（返回值） $-         使用Set命令设定的Flag一览 $*         全部參数列表。如"$*"用「"」括起来的情况、以"$1 $2 … $n"的形式输出全部參数。 [email protected]         全部參数列表。如"[email protected]"用「"」括起来的情况、以"$1" "$2" … "$n" 的形式输出全部參数。
 $# 加入到Shell的參数个数 $0 Shell本身的文件名称 $1～$n 

Demo Sample:

#!/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" "$*"printf "The complete list is%s\n" "[email protected]"printf "The complete list is%s\n" "$#"printf "The complete list is%s\n" "$"printf "The complete list is%s\n" "$"printf "The complete list is%s\n" "$"

Results:

[[email protected] ~]$ bash params.sh 123456 QQThe complete list is 24249The complete list isThe complete list is 0The complete list is 123456 QQThe complete list is 123456The complete list is QQThe complete list is 2The complete list is params.shThe complete list is 123456The complete list is QQ

Many other explanations are shown in the following documents
: http://www.tldp.org/LDP/abs/abs-guide.pdf

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Linux in Shell variable $#,[email protected], $0,$1,$2 meaning explanation: