Linux variables #, @, 0, 1, 2, *, $, $? Linux Variables

Linux variables #, @, 0, 1, 2, *, $, $? Linux Variables
Linux variables #, @, 2, *, $, $

Let's first write a simple script and then explain the meaning of each variable after execution # touch variable # vi variable script content is as follows :#! /Bin/shecho "number :#"

Echo "scname: 0"

Echo "first: 1" echo "second: 2"

Echo "argume: $ @"

Echo "show parm list: $ *"

Echo "show process id: $"

Echo "show precomm stat: $"

Save and exit to grant the script execution permission # chmod + x variable to execute the script #./variable aa bbnumber: 2

Scname:./variable

First: aa

Second: bb

Argume: aa bbshow parm list: aa bb

Show process id: 24544 show precomm stat: 0

The displayed result shows: $ # number of parameters passed to the script $0 is the name of the script itself $1 is the first parameter passed to the shell script $2 is the second parameter passed to the shell script $ @ is a list of all parameters passed to the script $ * shows all parameters passed to the script using a single string, different from location variables, a maximum of nine parameters $ indicates the ID of the current process in which the script runs. $ indicates the exit status of the last command. 0 indicates no error. Others indicate errors.