The meaning of the shell variable $ #, $ @, $0, $1, $2 in linux

The meaning of the shell variable $ #, $ @, $0, $1, $2 in linux
Variable description $ shell's PID (processID) $! Background ProcessID $? End code of the last command (Return Value) $-Flag list Set using the Set command $ * List of all parameters. For example, if "$ *" is enclosed by "$1 $2 $3... $ n", all parameters are output. $ @ List of all parameters. For example, if you use "$ @" and "enclose it with" $1 "" $2 "... output all parameters in the form of "$ n" $ # number of parameters added to the Shell $0 name of the Shell itself $1 ~ $ N parameter values added to Shell. $1 is the 1st parameter, and $2 is the 2nd parameter ....