Copy and paste a folder

I am trying to make a copy of an OpenFoam tutorial folder to my desktop through Ubuntu since I don’t want to mess up the original files. I use the command line:
cp -r $FOAM_TUTORIAL /mnt/c/Users/username/Desktop

but this error pops up
cp: missing destination file operand after ‘/c/Users/username/Desktop’

Can I get any help with this?

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Author: user421564

How to display Apache Tomcat metrics on Ubuntu (Like cPanel’s metrics)

I need a way to display metrics like number of visitors, location of visitors and so on using Ubuntu and Apache Tomcat.
I would like it to work in a cPanel or Webmin fashion where the data is displayed on a webpage and I can access it from another machine (something lightweight too, because my server is a weak machine).

I am using Apache Tomcat v9.0.36 and Ubuntu 18.04.4 LTS.


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Author: Ivan Dimitrov

how to print tilde symbol on ubuntu

I have environment variable export var=~/.ssh/etc

when I do echo "$var" I get /home/user/.ssh/etc

is there anyway that I can print this variable and get ~/.ssh/etc as an output?

Please Note, that puting it inside single quotes like this export var='~/.ssh/etc' is not an option for me

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Author: Kingindanord

Is the 5.3 linux kernel fully supported as LTS on Ubuntu 18.04?

I’m a bit confused about Ubuntu’s announcement to switch to a Rolling Kernel.

  1. I’ve noticed some of my Ubuntu 18.04 servers are now running the 5.3 kernel, which the blog post seems to imply is the linux-aws-edge kernel, or not for production workloads. Is that the case, or is the rolling kernel installing vs. the linux-aws-edge? I’m not sure because I see both linux-aws-edge ( and linux-aws ( on

  2. Even if this is the production-ready 5.3 kernel being installed by the new Rolling Kernel model, what does this do to LTS support? It appears to break LTS support see the “Kernel support schedule” section, am I interpreting this right?

  3. Why would Canonical make this opt-out vs. opt-in?

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Author: stantonk

Circumventing Local Subnet Control Restrictions with Iptables

I have three wireless speakers that, for security reasons, only permit local subnet control. My network is setup such that the wired and wireless devices are on separate subnets, so right now the speakers cannot be used from the wired clients. I can setup a Ubuntu 18.04 virtual machine with interfaces in both subnets, but am not familiar enough with iptables to configure the forwarding correctly.

The speakers have IP addresses,, and The wired clients exist in the subnet. Each speaker needs to have two ports (8000, 9000) reflected. My reflection virtual machine has interfaces in both subnets, and What is the correct iptables setup to do the following: -> via -> via -> via -> via -> via -> via

Does this setup make sense? Short of changing out the speakers for ones that are more compatible with my network setup, is there an easier way to do this that I did not think of?


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Author: user986713

Linking nodes in a cluster to run a single instance of a docker container

In this cluster, there are 11 identical nodes, each with 16gb of memory. So far, I’ve been able to connect each node of the cluster to a docker swarm hosted on the control node. My end goal is to run a single instance of a container that utilizes the resources of each node so the total memory of that container would be 176gb. How should I accomplish this?

Each worker node is running Ubuntu Server 20.04 and the control node is running Ubuntu Desktop 16.04, all with docker engine 19.03.8.

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Author: AJ_4real

Change Font color and size when booting into CLI ubuntu 20.04 LTS

Change Font color and size when booting into CLI ubuntu 20.04 LTS

I was wondering if there was a way to increase font size and change font colour when booting into CLI.
The font is small and white on black, I want it to change the font colour.
If anyone can help, that would be great.
I am ready to provide any system details if needed.

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Author: Ammar