Ceci est une ancienne révision du document !
Welcome back to another edition of Questions and Answers! In this section, we will endeavour to answer your Ubuntu questions. Be sure to add details of the version of your operating system and your hardware. I will try to remove any personally identifiable strings from questions, but it is best not to include things like serial numbers, UUIDs or IP addresses. If your question does not appear immediately, it is just because there is such a lot, and I do them, first-come-first-served.
NOTE: Guys, with the latest Google hack, my Gmail accounts are all in limbo, if you sent me any messages there, I will get to those only when it unfreezes again.
Many moons ago, I was an FSE who had to service clients in rural areas. The company I worked for was subcontracted to IBM. IBM would get all the contracts and subcontract out everything that wasn’t sales. With these shiny machines, IBM sold OS/2. For most customers, this was a big change from plain DOS input. With OS/2 you actually got to use the computer mouse. This object with a weighted ball, and buttons confused a lot of old people. It was easy to tab to where you needed to enter the next bit of information, and the mouse operation slowed down some people’s business operations by as much as 80%. Understandably, there were a lot of angry managers and supervisors. We would be called out a lot for dirty muse balls, etc. However, one day I had to drive four hours to a client, who just could not get the hang of the new application. I stood behind the old fellow and walked him through the use of the application – to get them to speed up their work flow. The very last page, for some or other reason, had the finish button at the top-right. I watched him search for a minute for the OK button. I said helpfully, “top-right, finish”. He was so confused, he asked me, my right or your right? As I was standing right behind him, my right was his right. I answered, “it’s the same right”. He looked at me funny and I assume the penny dropped. Then, to cover up, he said, “well dammit, how do I know that? You could be left-handed…” Laughing all the way home made the trip a lot shorter!
Q: I just set up Ubuntu server with docker on an old PC. The networking part has me perplexed. I can’t ping my server from my windows 10 laptop. The replies are “Destination host unreachable.” I have even disabled the firewall with sudo ufw disable. How can I troubleshoot this?
A: My first thought would be to ping back. On your server, see if you can ping the windows machine. If you can’t, see if both sides can ping the gateway or router. Then look carefully at your subnetting – on /24, for example, 192.168.1.1 and 192.168.2.1 are not quite what you want.
Q:Got permission denied while trying to connect to the Docker daemon socket at unix:/var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.24/build?buildargs=%7B%7D&cachefrom=%5B%5D&cgroupparent=&cpuperiod=0&cpuquota=0&cpusetcpus=&cpusetmems=&cpushares=0&dockerfile=Dockerfile&labels=%7B%7D&memory=0&memswap=0&networkmode=default&rm=1&shmsize=0&t=getting-started&target=&ulimits=null&version=1: dial unix /var/run/docker.sock: connect: permission denied A: Use sudo, or add your user to the docker group: sudo usermod -aG docker $USER Q: When I run my script, I get —- ‘python’: No such file or directory —- I am very new to all this and people are giving me all kinds of advice that does not seem to help. I am learning from books at the library, so I can’t really ask them questions. A: I suspect your book is old. Python moved on, so “python” usually points to Python 2, and we are now at Python 3. Check your shebang entry, so that it points to Python 3. Type ‘which python3’ (no spaces or you will get the python path), and copy the result to your script. Q: NuGet and Chocolatey got me to move to Ubuntu. Now I am sitting here in front of my freshly installed Ubuntu 20.04 and wanting to just install my apps again with any one of these two. But I can’t. But I have to. See my dilemma? A: No, not really. Nuget and Chocolatey are windows package managers to install windows applications. In Linux, you just open a terminal and type: sudo apt install <package name> – otherwise open your software centre – if you have a desktop version of Ubuntu installed – and browse. There are other stores in Ubuntu too. Q: My server is Ubuntu 20.04 with just the basics. I logged in with Putty and I see this. root@agitated_darwin:~# I tried duckduckgo on Darwin, but that is an OSX codename. It is supposed to be focal fossa. What does this actually mean? <image removed> A: Spinning up an Ubuntu server, it is given a random name. Unless you give it one when spinning it up. Darwin in this case is a Scientist name. Q: This is what I want to do; found it on StackOverflow with no answers: How can I set a default code in Codeblocks which appears every time when I open a new empty file. I put my template code (sample code) in Settings→ Editor→ Default code. But it is not working when I create a new Empty file. OS: ubuntu 20.04, code blocks version: 20.03. A: I suggest asking on their forum, but I would think an empty file is an empty file (if it were not empty…). When you edit “default code”, it is for a source file or header, not an empty file. If I remember correctly, the changes take place only when you exit and save. Q: So following this tutorial on how to install java, I did the following: sudo apt install default-jre, but “java -version” shows that java was not found. So what now? A: Have you tried installing openjdk? The JDK usually includes the JRE and all the other tools you need to create Java programs. Q: HermanH, [24.11.20 16:34] Can you do a cURL tutorial? I can’t read man pages. They are like rubbing yourself up a pineapple. A: Can do. Keep your eyes on future issues. Q: I am trying to do some tutorials, and I just upgraded from Ubuntu 18 to 20. Ubuntu 18 was my first linux install. Somehow I can’t run YUM commands. I can’t even install it. A: YUM is an rpm-based package manager (SUSE, RH, ORACLE). APT is the debian-based distro package manager. It’s like trying to fit a Toyota gearbox on a BMW. Q: I miss glasswire on Windows. I went to alternative.to to get an alternative, but the options are confusing. Netdata doubly so. Can you help me? https://alternativeto.net/software/glasswire/?platform=linux A: I suggest Portmaster and OpenSnitch, the rest are white noise. (The most popular is not always the best alternative). Q: I need to encrypt my WD pocket drive so that I can take my work to the office. The thing is, the machine at the office also needs to unlock this drive, yet the users and systems are different. Unencrypted drives are not allowed. What is my best bet? A: I am inferring here, as the question needs more meat. We have done an article on Veracrypt. Once encrypted, the drive will unencrypt on Linux, Mac or Windows, with the password and/or PIN. Choose a file system that works at home as well as at work. Q: I just upgraded from an i3 dual-core to a beast machine with 16 cores. I am disappointed that it is only about twice as fast. Why can’t Ubuntu be faster? A: The thing with parallel processing is, even if you have 128 cores, usually the next thread is waiting for the previous one to finish. When you bake bread, it does not help to take out the jam before the dough is mixed? Parallel is not really parallel as any program is linear. It has nothing to do with Ubuntu. Q: My Ubuntu is 14.04. Sometimes I can run the latest and greatest software and applications, and sometimes I can’t. Why is this? Don’t tell me to upgrade, I am happy the way it is. A: Simple, dependencies. This is why Snaps, AppImages and so forth exist. Different versions of software are built with different toolchains, so even if you try to compile it yourself, it will not allow it, as your version of Ubuntu may not support the newer technologies. I am not telling you to upgrade, but if you want the latest and greatest, an old OS is not the way to go. Q: Why does the mv command just overwrite an existing file without a peep? A: If you want it to “peep”, you need to use mv -i … or alias it to something like mov. Q: I'm trying to install ros melodic on ubuntu 20.04, but I get the following message: Depends: ros-melodic-desktop but it is not going to be installed …blah blah blah. All I am met with is dependency issues when trying to install the missing files manually. A: According to their website, it is only for Ubuntu 16.04 and 18.04. Q: How can I know what is inside a specific Ubuntu install by default? Let's say it is running off a live CD and has not been tampered with. There were no apps installed after it booted. How can I know what is inside without running a VM and mounting the same CD? A: Each release has a manifest file. You can download those and look inside. Go to http://releases.ubuntu.com/, pick your release, look inside the folder for the manifest. Q: How can I see/verify if my VPN is working from the command-line? A: I don’t use any, but try: curl ipinfo.io and see if it correctly identifies the location. There may be an easier or better way, but that is what I like about Linux, many ways to accomplish a task. If there are any readers with better suggestions, mail us: misc@fullcirclemagazine.org Q: How to solve? I am using Ubuntu to RDP to our company server, using Remmina. All is set up correctly – like before the new Ubuntu. When I am connecting, immediately blue screen me signing out. “Signing out” and log me off. I am working from home now, so I need it to work. I asked the support department and they say they do not support Linux. A: That is not an Ubuntu/Linux issue, tell the lazy support staff to lift their butts and disconnect your open sessions on the Windows server. Q: How can I make Ubuntu more hard-core at start up? A: I am not sure I understand the question, but… You can use any boot image you want with Plymouth to make it appear whatever feeling it is you want. You can also just remove the “quiet splash” from kernel command-line (grub), then the boot messages will scroll by (not sure how many milliseconds it will be these days as PC’s have become so fast).