Raspberry Pi 4
Wow, Raspberry Pi 4 is now available with 8GB of DDR4 memory! This is still a crazy good value for something that costs less than $100 ($75 for just the Raspberry Pi itself, actually) and runs modern operating systems with most of functionality you come to expect from a Linux desktop!
I needed to forward X11 output from one of my Linux servers recently to run virt-manager (manager for virtual machines in KVM), and because it’s been a while I had to download and install X11 server again.
I love reading man pages for even the most basic Unix commands like ls, because there’s always something interesting to learn. Today I discovered that it’s possible to sort ls output by file size.
As I mentioned, I’m building a new Linux based desktop PC – currently running RHEL 8. Since I’m planning it as a primary desktop system for my home lab, I want to eventually migrate workflows from MacBook Pro to the new PC – and this means I want to use my existging LG 5K UltraFine 27” display. This seemed like an interesting Unix Tutorial Project from the very start!
Apparently, Debian installer doesn’t install or activate sudo by default. This means that sudo command is not found the only privilege escalation method available is becoming root via su command. Since I like and use sudo daily, I decided to install and setup it on Debian VM.
I’m slowly improving my Python skills, mostly by Googling and combining multiple answers to code a solution to my systems administration tasks. Today I decided to write a simpe converter that takes Epoch Time as a parameter and returns you the time and date it corresponds to.
I had a server run out of space recently, to the point that it couldn’t complete the yum update. This server ended up corrupting a yum packages database.
Now and then you may notice that apt-get upgrade command keeps a few packages back, meaning they don’t get upgraded. This quick post shows what you can do about it and how to get all the packages upgraded.
Unlike chmod command, chown only becomes useful if run with elevated (root) privileges. In Linux, it is most commonly used with the help of sudo command.
I know that the upcoming Linux Mint release will be based on the just-released Ubuntu 19.04, but just couldn’t wait this long to try Ubuntu 19.04 and all the improvements it brings. So my past few week’s project has been to install Ubuntu 19.04 on my Dell XPS 13 9380 laptop.
This week’s Unix Tutorial Project is super geeky and fun: I’m setting up text-based email archive system using Mutt (NeoMutt, actually), OfflineIMAP and hopefully NotMuch. Will publish a project summary on the weekend.
Call me old fashioned, but I still prefer using ifconfig command. It’s not as cool as the ip command found in recent Linux distros, but familiar and universal enough to be found pretty much everywhere else. This post shows how to install packages to make ifconfig working again.
I really like the Hack font – it’s used in my terminal apps on MacOS, Linux and even Windows workstations. This short post demonstrates how to install Hack font, but you can use the steps to configure any other TrueType Font (TTF) on your system.
One of the most useful and powerful basic Unix commands, chown command allows you to change ownership of specified files and directories – change user or group owner.
As you can imagine, SSH keypairs – combinations of private and public keys – are vital elements of your digital identity as a sysadmin or a developer. And since they can be used for accessing source code repositories and for deploying changes to production environments, you usually have more than one SSH key. That’s why it’s important to know how to inspect SSH key fingerprints.
Since awk field separator seems to be a rather popular search term on this blog, I’d like to expand on the topic of using awk delimiters (field separators).
I have a tiny server in home office, it used to be a Window 8 based entertainment box but I reinstalled it with Ubuntu 18.10 recently enough to run home automation. There has’t been any particular function assigned to this server but I have finally decided what role it will play: it will be an always-on Ubiquiti UniFi controller for my home office network!
diff is a mightly command line tool found in most of Unix and Unix-like operating systems. diff helps you to find differences between files and directories.
Now and then, especially when working on a development environment, you need to stop multiple Docker containers. Quite often, you need to stop all of the currently running containers. I’m going to show you one of the possible ways.
If for whatever reason you stop using a certain service in your Ubuntu install and would like to disable automatic restarting for it upon system reboot, all it takes to do it is just one command line.
Screen Shot 2019-01-05 at 17.29.36.png
dd command, that is pretty much guaranteed to be pre-installed on your Linux or Unix server, can be used to quickly get an understanding of the I/O capability of available storage.
You probably know about curl command: it’s great for downloading web pages or files from a Unix command line. But there’s another great usage curl command has: testing TCP ports connectivity.
One of the very first questions a Linux user asks is about confirming the release (OS version) in use. Knowing release helps with highlighting software dependencies and compatibilities, confirms availability of certain features in your OS and simplifies the process of system administration – certain releases have a preferred set of commands for day-to-day management.
New Linux users often get puzzled by the “mkdir: cannot create directory” errors when taking first steps and trying to learn basics of working with files and directories. In this short post I’ll show the two most common types of this mkdir error and also explain how to fix things so that you no longer get these errors.
IMPORTANT: This is a post from another blog of mine, which I’m shutting down. I like the way these virtualization concepts were worded in such a relatively simple way, so I’m keeping the post 🙂
Many of us have heard about hardware virtualization, but as far as I can see there is still a lot of confusion around this term and surrounding technologies, so today I’ve decided to give a really quick intro. Some time in the future, I’ll probably cover this topic in detail.
I explained how to read the /proc/mdstat in my recent post How To Identify RAID Arrays in Linux, so today is a super quick follow up using one of my systems.
Because I own a number of Raspberry Pi systems, I get roughly the same question quite regularly about each one of them: how can I confirm what this Raspberry Pi model is from the command line? The reason I usually want to know is because the model of the Raspberry Pi hints the Raspbian release that will support it (older Raspbian releases do not have support for the most recent models of Raspberry Pi).
When you want to save yourself from typing an unwieldy command over and over again you can create and use an alias for it. It will then act as a shortcut to the larger command, which you can type and run instead.
The tmux tool, or the terminal multiplexer, is great for allowing you to run multiple terminals side by side. What’s even better is that you can somewhat customize its behavior using the tmux.conf file. The meta key is the prefix you press before you issue a command that controls tmux so you can, for instance, split the terminal in two. By default it is set to CTRL-B, and this is how you can change that.
Some properties of ext2, ext3, and ext4 file systems on Linux and UNIX can be tuned on the fly using the tune2fs command. This includes the file system’s label.
The unrar program, which serves to open and extract popular .rar archives, is often available for install from repositories of a given Linux distribution. That should make installing it easy by using your distribution’s package management system. That can be either a graphical user interface program like Ubuntu Software Center, or a command like tool like apt-get.
Finding out sizes of files and directories in Linux is done using the du command, which estimates their disk space usage. The du command can be used with options that allow you to customize the results you get.
The visudo command is a safe and secure way of editing the /etc/sudoers file on UNIX and Linux systems. /etc/sudoers is instumental for gaining privileged access via sudo command.
The visudo command is a safe and secure way of editing the /etc/sudoers file on UNIX and Linux systems. /etc/sudoers is instumental for gaining privileged access via sudo command.
The mkfs command available in UNIX and Linux operating systems is used to create file systems on various storage devices or partitions. It stands for “make filesystem”, and creating a file system is essentially an equivalent to what is popularly known as “formatting” a disk or a partition with a particular file system type (such as FAT32 or NTFS in Windows).
I had to download a piece of software today for one of the servers which I haven’t used in a while. A question of confirming the 64bit CPU capability came up, and I realized that I never mentioned it here on Unix Tutorial.
I’ve just been asked a question about changing the ownership of files from one Unix user to another, and thought it probably makes sense to have a quick post on it.
Yesterday in my post on numeric userids instead of usernames, I touched briefly the problem of recovering the username if you only know the userid it once had. Today I would like to show you another option which may be available to you when it comes to recovering the usernames of removed users by their userid.
As you know, every file in your Unix OS belongs to some user and some group. It is very easy to confirm the ownership of any file because user id and group id which own the file are always linked to the file. However, sometimes you can’t tell which user owns the file, and today I’m going to explain why. It’s a rather lengthy post and a complicated matter, so please leave questions or comments to help me polish this article off.
Today I’d like to show you the basic usage of rsync – a wonderful, old and reliable tool for incremental data transfers and synchronization of local directories or even data between different Unix systems.
If you’re interested in what exactly your Ubuntu system has got installed, there’s a command you can use to list the packages along with their versions and short descriptions.
If you’re logged in at some remote Linux system and need to quickly confirm the amount of available memory, there’s a few commands you will find quite useful.
Certain situations require you to quickly confirm which files between two directories are different, and while your particular requirements may suggest writing a script for this task, I want to make sure you’re familiar with the basics first – majority of directory comparisons can be done using diff command (yes, that’s right – the same one used for comparing files).
Showing your processes in a hierarchical list is very useful for confirming the relationship between every process running on your system. Today I’d like to show you how you can get tree-like processes lists using various commands.
As you know, Unix filesystems store a number of timestamps for each file. This means that you can use these timestamps to find out when any file or directory was last accessed (read from or written to), changed (file access permissions were changed) or modified (written to).
Another quick answer to the question I see a lot in search queries on this blog: listing directories in a directory. I take it that this question means showing a list of only the directories and not other files under a certain location of your Unix filesystem.
Very quick tip for you today, I just see that many of visitors of this block are curious how they can find a directory in Unix – and so here’s a command to help you do just that.
When you’re trying to clean up your filesystems and reclaim some space, one of the first things you’ll want to do is to confirm the largest directories and individual files you have. This can be easily done using two Unix commands: find command and du command.
To some this may seem like a trivial task, but I see great interest from Unix/Linux beginners arriving to this blog: how exactly does one confirm what a symlink points to?
Unix Tutorial Projects: Compiling Brave browser on Linux Mint
Brave browser
Some of you may have noticed: I added the link to Brave browser to the sidebar here on Unix Tutorial. That’s because I’m giving this new browser a try and support its vision to reward content producers via Brave’s Basic Attention Token cryptocurrency. If you aren’t using Brave browser already, download and try Brave browser using my link.
In this Unix Tutorial Project, just because it seems fun and educational enough, I’ll attempt compiling Brave browser on my Dell XPS 13 laptop running Linux Mint 19. There’s a much easier way to install Brave browser from official repositories: official instructions here.
Make sure you have enough disk space
This project suprised me a bit. I had 20GB of space and thought it would be enough! Then I saw the git download alone would be almost 15GB, but hoped I had enough.
I was wrong! Ended up resizing Windows 10 partition on my laptop to free up space for another 100GB Linux filesystem.
The final space consumption is 67GB, that’s a lot of source code with an impressive amount (32 thousand of them!) object files (intermidiary binary files you need when compiling large project. they’re used to make up the final binary:
[email protected]:/storage/proj# du -sh brave-browser
67G brave-browser
Prepare Linux Mint 19 for Compiling Brave Browser
Following instructions from https://github.com/brave/brave-browser/wiki/Linux-Development-Environment, I first installed the packages:
[email protected]:~$ sudo apt-get install build-essential libgnome-keyring-dev python-setuptools npm
[sudo] password for greys:
Reading package lists... Done
Building dependency tree
Reading state information... Done
build-essential is already the newest version (12.4ubuntu1).
The following package was automatically installed and is no longer required:
libssh-4
Use 'sudo apt autoremove' to remove it.
The following additional packages will be installed:
gir1.2-gnomekeyring-1.0 gyp libc-ares2 libgnome-keyring-common libgnome-keyring0 libhttp-parser2.7.1 libjs-async libjs-inherits libjs-node-uuid libjs-underscore
libssl1.0-dev libssl1.0.0 libuv1-dev node-abbrev node-ansi node-ansi-color-table node-archy node-async node-balanced-match node-block-stream node-brace-expansion
node-builtin-modules node-combined-stream node-concat-map node-cookie-jar node-delayed-stream node-forever-agent node-form-data node-fs.realpath node-fstream
node-fstream-ignore node-github-url-from-git node-glob node-graceful-fs node-gyp node-hosted-git-info node-inflight node-inherits node-ini node-is-builtin-module node-isexe
node-json-stringify-safe node-lockfile node-lru-cache node-mime node-minimatch node-mkdirp node-mute-stream node-node-uuid node-nopt node-normalize-package-data node-npmlog
node-once node-osenv node-path-is-absolute node-pseudomap node-qs node-read node-read-package-json node-request node-retry node-rimraf node-semver node-sha node-slide
node-spdx-correct node-spdx-expression-parse node-spdx-license-ids node-tar node-tunnel-agent node-underscore node-validate-npm-package-license node-which node-wrappy
node-yallist nodejs nodejs-dev python-pkg-resources
Suggested packages:
node-hawk node-aws-sign node-oauth-sign node-http-signature debhelper python-setuptools-doc
Recommended packages:
javascript-common libjs-jquery nodejs-doc
The following packages will be REMOVED:
libssh-dev libssl-dev
The following NEW packages will be installed:
gir1.2-gnomekeyring-1.0 gyp libc-ares2 libgnome-keyring-common libgnome-keyring-dev libgnome-keyring0 libhttp-parser2.7.1 libjs-async libjs-inherits libjs-node-uuid
libjs-underscore libssl1.0-dev libuv1-dev node-abbrev node-ansi node-ansi-color-table node-archy node-async node-balanced-match node-block-stream node-brace-expansion
node-builtin-modules node-combined-stream node-concat-map node-cookie-jar node-delayed-stream node-forever-agent node-form-data node-fs.realpath node-fstream
node-fstream-ignore node-github-url-from-git node-glob node-graceful-fs node-gyp node-hosted-git-info node-inflight node-inherits node-ini node-is-builtin-module node-isexe
node-json-stringify-safe node-lockfile node-lru-cache node-mime node-minimatch node-mkdirp node-mute-stream node-node-uuid node-nopt node-normalize-package-data node-npmlog
node-once node-osenv node-path-is-absolute node-pseudomap node-qs node-read node-read-package-json node-request node-retry node-rimraf node-semver node-sha node-slide
node-spdx-correct node-spdx-expression-parse node-spdx-license-ids node-tar node-tunnel-agent node-underscore node-validate-npm-package-license node-which node-wrappy
node-yallist nodejs nodejs-dev npm python-pkg-resources python-setuptools
The following packages will be upgraded:
libssl1.0.0
1 upgraded, 80 newly installed, 2 to remove and 286 not upgraded.
Need to get 10.7 MB of archives.
After this operation, 37.7 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://archive.ubuntu.com/ubuntu bionic/universe amd64 libgnome-keyring-common all 3.12.0-1build1 [5,792 B]
Get:2 http://archive.ubuntu.com/ubuntu bionic/universe amd64 libgnome-keyring0 amd64 3.12.0-1build1 [56.1 kB]
...
Get:81 http://archive.ubuntu.com/ubuntu bionic/universe amd64 npm all 3.5.2-0ubuntu4 [1,586 kB]
Fetched 10.7 MB in 2s (6,278 kB/s)
Extracting templates from packages: 100%
Preconfiguring packages ...
(Reading database ... 267928 files and directories currently installed.)
...
You should end up with a whole bunch of npm (node-*) packages installed.
You need to install gperf package as well – npm run build (last step below) failed for me because gperf wasn’t found.
and then do npm install. This is how it should look:
git cloning Brave browser
Download Chromium source code using npm
npm run init command will download the source code of Chromium browser (open source original Chrome is being built on), Brave browser is based on it. This should take a while – on my 100Mbit connection it took 25min to download 13.5GB (that’s comporessed, mind you!) of Chromium’s source code and then another 25min to download the rest of dependencies:
[email protected]:~/proj/brave-browser$ npm run init
> [email protected] init /home/greys/proj/brave-browser
> node ./scripts/sync.js --init
git submodule sync
git submodule update --init --recursive
Submodule 'vendor/depot_tools' (https://chromium.googlesource.com/chromium/tools/depot_tools.git) registered for path 'vendor/depot_tools'
Submodule 'vendor/jinja' (git://github.com/pallets/jinja.git) registered for path 'vendor/jinja'
Cloning into '/home/greys/proj/brave-browser/vendor/depot_tools'...
Cloning into '/home/greys/proj/brave-browser/vendor/jinja'...
Submodule path 'vendor/depot_tools': checked out 'eb2767b2eb245bb54b1738ebb7bf4655ba390b44'
Submodule path 'vendor/jinja': checked out '209fd39b2750400d51bf571740fe5ba23008c20e'
git -C /home/greys/proj/brave-browser/vendor/depot_tools clean -fxd
git -C /home/greys/proj/brave-browser/vendor/depot_tools reset --hard HEAD
HEAD is now at eb2767b2 Roll recipe dependencies (trivial).
gclient sync --force --nohooks --with_branch_heads --with_tags --upstream
WARNING: Your metrics.cfg file was invalid or nonexistent. A new one will be created.
________ running 'git -c core.deltaBaseCacheLimit=2g clone --no-checkout --progress https://chromium.googlesource.com/chromium/src.git /home/greys/proj/brave-browser/_gclient_src_JunGAS' in '/home/greys/proj/brave-browser'
Cloning into '/home/greys/proj/brave-browser/_gclient_src_JunGAS'...
remote: Sending approximately 14.36 GiB ...
remote: Counting objects: 161914, done
remote: Finding sources: 100% (949/949)
Receiving objects: 3% (362855/12095159), 163.33 MiB | 10.38 MiB/s
[0:01:00] Still working on:
[0:01:00] src
Receiving objects: 5% (632347/12095159), 267.23 MiB | 9.94 MiB/s
[0:01:10] Still working on:
[0:01:10] src
...
├─┬ [email protected]
│ ├── [email protected]
│ ├─┬ [email protected]
│ │ └── [email protected]
│ ├── [email protected]
│ ├── [email protected]
│ ├── [email protected]
│ ├─┬ [email protected]
│ │ ├─┬ [email protected]
│ │ │ └── [email protected]
│ │ └─┬ [email protected]
│ │ ├─┬ [email protected]
│ │ │ ├── [email protected]
│ │ │ └─┬ [email protected]
│ │ │ └── [email protected]
│ │ └── [email protected]
│ └── [email protected]
└── [email protected]
npm WARN [email protected] requires a peer of [email protected]^5.0.0 but none was installed.
npm run build
> [email protected] build /home/greys/proj/brave-browser/src/brave/components/brave_sync/extension/brave-crypto
> browserify ./index.js -o browser/crypto.js
Hook '/usr/bin/python src/brave/script/build-simple-js-bundle.py --repo_dir_path src/brave/components/brave_sync/extension/brave-crypto' took 27.09 secs
Running hooks: 100% (83/83), done.
Build Brave Browser from Source Code
Here we go! Let’s build this thing. Should take an hour or two on a fast PC:
This is a release build, meaning this is a fully performance and release-grade build of the source code. If you’re going to contribute to Brave browser open source project, you should know that npm run build (without Release parameter) will provide a debug build.
This is how the end process looks (took a few hours to compile on the 8-core CPU of my XPS laptop):
Brave browser fully compiled
Start the Newly built Brave Browser
This is it! Let’s try starting the browser, this should complete our Unix Tutorial project today:
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Recommended Software
I use Brave browser, it's awesome:
I'm also a fan of SetApp for macOS:
IT Consultancy
I'm a principal consultant with Tech Stack Solutions. I help with cloud architectrure, AWS deployments and automated management of Unix/Linux infrastructure. Get in touch!
Mastery Books by Michael W Lucas
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Apache httpd Web Server
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Ubuntu 20.10
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Linux System Calls and their Numbers
macOS Catalina
my crontab in nano editor on macOS
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Enabling ZFS compression
Unix Tutorial Digest
Docker Hub
Disabling atime in ZFS
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watch ifconfig command with 0.2s interval
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Wow, 
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Brave browser
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