Explanation of the meaning of shell variable $#,$@,$0,$1,$2 in Linux

Source: Internet
Author: User

The meaning of shell variable $#,[email protected],$0,$1,$2 in Linux is explained:
Variable Description:
$$ 
The PID of the shell itself (ProcessID)
$! 
PID of the Shell's last running background process
$?
End code of the last Run command (return value)
$- 
Flag at a glance using the SET command
$* 
All parameter lists. such as "$*" in the Case of "" ","$ $ ... $n"All parameters in the form of output.
[email protected]
All parameter lists. such as "[email protected]" in the case of "" ", in order to"$" "$" ... "$n"All parameters in the form of output. Attention and$*The difference
$# 
Number of arguments added to the shell
$
The name of the shell itself
$1~ $n
Each parameter value added to the shell. $ $ is the 1th parameter, and the $ = is the 2nd parameter ....

Example:

Results:

Notice the difference between $* and [email protected]

Linux shell variable $#,[email protected], $0,$1,$2 meaning explanation

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