Get Linux device IP address from com port using PowerShell

Question

I am currently setting up a test ARM based board running Linux and I need to access it from a Windows machine. This test board is connected via the com port using a USB-to-Serial cable. I am using PowerShell to run commands and control the test board. I'm stuck at a stage where I need to query the test board to find out its IP Address and store it in a variable on my Windows host.

This is what I'm using to display the IP Address:

$port.WriteLine("ifconfig | grep -A 1 'gphy' | tail -1 | cut -d ':' -f 2 | cut -d ' ' -f 1")

When I read the output from the console, I get the ifconfig command as well as the IP Address into my variable:

$ipAddr = $port.ReadExisting()
$ipAddr

The output is something like:

ifconfig | grep -A 1 'gphy' | tail -1 | cut -d ':' -f 2 | cut -d ' ' -f 1
123.33.33.150
#

I fail to get only the IP Address as a string. Is my approach correct or am I doing something wrong here? What is the best way for querying for the IP Address?

What is puzzling you? The fact that the variable also contains the entire command? How is $port defined/created? — Lieven Keersmaekers
– Lieven Keersmaekers, Commented Jan 3, 2018 at 5:43

vonPryz · Accepted Answer · 2018-01-03 06:59:11Z

2

Just use either a substring or a regex to extract the value(s) you'd want.

$ipaddr = @"
ifconfig | grep -A 1 'gphy' | tail -1 | cut -d ':' -f 2 | cut -d ' ' -f 1
123.33.33.150
"@
$regex = '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}'
(($ipaddr | Select-String -Pattern $regex).Matches).Value

Results

123.33.33.150

edited Jan 3, 2018 at 6:59

vonPryz

24.3k10 gold badges58 silver badges69 bronze badges

answered Jan 3, 2018 at 6:36

postanote

16.4k3 gold badges17 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

bluuf Over a year ago

This is by far the most simple way to do this.

Sudeep Mohanty Over a year ago

@postanote I was wondering if I should take the regex route. Like everyone's suggested, this is by far the easiest way. Just to add to your answer, I will get my final IP Address in $matches[0]. This all but solves my problem. Thank you!

kunif · Accepted Answer · 2018-01-03 06:57:58Z

1

In ARM Linux, it will be possible to set echo off of the port connected to Windows.
For example, if the connection port is /dev/ttyS0, add the following line to startup script.

stty -F /dev/ttyS0 -echo

However, unless you change the setting, all the write data will not be echoed back in other uses.

answered Jan 3, 2018 at 6:57

kunif

4,4002 gold badges13 silver badges35 bronze badges

Collectives™ on Stack Overflow

Get Linux device IP address from com port using PowerShell

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related