bash 常用指令 - 《Linux笔记》

数组

Variables	Description
$0	The filename of the current script.
$1-$9	Stores the names of the first 9 arguments or can be used as the arguments’ positions.
$$	The process id of the current shell.
$#	The number of arguments supplied to a script.
$*	Stores all the command line arguments by joining them together.
$@	Stores the list of arguments as an array.
$?	Specifies the exit status of the last command or the most recent execution process.
$!	Shows the id of the last background command.
$-	Shows the options set used in the current bash shell.