The meaning of Shell scripting variable $#,$*,$$,$@,$0,$1,$2,$?

Parameter description

1:$# indicates the number of arguments passed into the script

2:$* indicates the execution of a script passed in the parameter list

3:$$ represents the Process ID

4:[email protected] means that the execution script passes all parameters

5:$0 represents the execution script name

6:$1 represents the first parameter

7:$2 represents the second argument

8:$? Indicates script execution status 0 Normal, other indicates error

Experiments and results (shelltest.sh)

#!/bin/SHEcho "parm number is: $#"Echo "parm list is: $*"Echo "All parm are: [email protected]"Echo "process is: $$"Echo "file name is: $"Echo "The first Parm is: $"Echo "stat is: $?"

Implementation and Results

Execution: Sh shelltest.sh "the first Parm" "The second Parm"

Parm number Is:2
Parm List Is:the First parm the second parm
All Parm is:the First parm the second parm
Process is:28669
File name is:shellTest.sh
The first parm is:the first parm
Stat is:0

Reprinted: 51859503

Shell script variable $#,$*,$$,[email protected], meaning of $0,$1,$2,$?