Your awesome title

Welcome to Jekyll!

2026-09-05T12:52:43+00:00

You’ll find this post in your _posts directory. Go ahead and edit it and re-build the site to see your changes. You can rebuild the site in many different ways, but the most common way is to run jekyll serve, which launches a web server and auto-regenerates your site when a file is updated.

Jekyll requires blog post files to be named according to the following format:

YEAR-MONTH-DAY-title.MARKUP

Where YEAR is a four-digit number, MONTH and DAY are both two-digit numbers, and MARKUP is the file extension representing the format used in the file. After that, include the necessary front matter. Take a look at the source for this post to get an idea about how it works.

Jekyll also offers powerful support for code snippets:

def print_hi(name)
  puts "Hi, #{name}"
end
print_hi('Tom')
#=> prints 'Hi, Tom' to STDOUT.

Check out the Jekyll docs for more info on how to get the most out of Jekyll. File all bugs/feature requests at Jekyll’s GitHub repo. If you have questions, you can ask them on Jekyll Talk.

Blog

2026-09-05T00:00:00+00:00

Blog

This blog is based on Github page and jekyll.

Installation

It requires Ruby, RubyGems, and bundler.

The following command can install the prerequisites

sudo apt install ruby-full build-essential zlib1g-dev

Sometimes gem is hard to access in some regions. It is recommended to change the source link. As an example,

sudo gem source --add --remove https://rubygems.org/

where is the host of a mirror. The follow installs jekyll and bundler

sudo gem install jekyll bundler

Jekyll Themes

The blog is based on mediator theme. Download the theme and copy it into my own git directory by

git clone https://github.com/dirkfabisch/mediator

Usage

The blog can be used from source with bundle

bundle exec jekyll server

Upgrade

Bundler and Jekyll requires the correct version of Ruby. If Ruby is updated within the system upgrade, bundler and Jekyll both need to reinstall from gem. For example, when Ubuntu 22.04 is upgraded from Ubuntu 20.04, Ruby 3.0 would be installed, but bundler and Jekyll both requires Ruby 2.7. So the two programs would not processing correctly anymore.

To fix this problem, the direct approach is to reinstall bundle with gem.

sudo gem install bundler

Then, bundle can install all required packages by bundle install except webrick because webrick is no longer in the standard library of bundle. However, I have a network issue when run bundle add webrick. It shows “Could not reach host index.rubygems.org. Check your network connection and try again.” The straightforward method is to set a mirror by

bundle config mirror.https://rubygems.org

where is the host of a mirror. However, it still does not work for me, while the mirror still can be reached by ping, curl, and the browser with ipv4. So the problem is strange, but I fix it with root command.

sudo bundle config mirror.https://rubygems.org sudo bundle install sudo bundle add webrick

The ipv6 is also cloased because it seems that bundle only supports ipv4, but it is not sure if this process works.

Jekyll Syntax

This page introduces Markdown syntax used in Jekyll websites. These syntax examples are based on common usage in the Just the Docs theme.

1. Front Matter (YAML Header)

Front Matter is a YAML-formatted configuration block at the top of Jekyll pages, used to set page properties.

---
title: Page Title
layout: Layout Name
nav_order: Navigation Order
description: "Page Description"
permalink: /custom-url-path
---

Parameter Explanation:

title: Page title
layout: Layout template to use (e.g., home, default, page, etc.)
nav_order: Display order in navigation menu (lower numbers appear first)
description: Page description, used for SEO and page summaries
permalink: Custom URL path, overrides default filename-based path

2. Headings

Markdown uses # symbols to indicate heading levels, from # (level 1) to ###### (level 6).

# Level 1 Heading
{: .fs-9 }

## Level 2 Heading
{: .fs-8 }

### Level 3 Heading
{: .fs-7 }

Note: The Just the Docs theme supports adding attribute blocks after headings to set CSS classes, such as {: .fs-9 } for setting font size.

3. Attribute Blocks

Attribute blocks are used to add CSS classes or other attributes to the preceding element.

This is a text paragraph.
{: .fs-6 .fw-300 .text-red }

This is a paragraph.
{: .note }

Common CSS Classes:

.fs-9, .fs-8, .fs-7, .fs-6: Font sizes
.fw-300, .fw-400, .fw-700: Font weights
.text-red, .text-blue: Text colors
.note, .warning: Callout styles

4. Horizontal Rules

Create horizontal rules using three or more hyphens, asterisks, or underscores.

---

***

___

5. Blockquotes

Use > symbol to create blockquotes.

> This is a blockquote.
> It can span multiple lines.
>
> Empty lines separate quote paragraphs.

6. Links

Basic Links

[Link Text](https://example.com)

Links with Titles

[Link Text](https://example.com "Link Title")

Reference-style Links

This is a reference-style [example link][1].

[1]: https://example.com "Example Website"

7. Emphasis

Italic

*Italic Text*
_Italic Text_

Bold

**Bold Text**
__Bold Text__

Bold and Italic

***Bold and Italic Text***
___Bold and Italic Text___

8. Footnotes

Footnotes are used to add notes at the bottom of the page.

This is text containing a footnote[^1].

[^1]: This is the footnote content, displayed at the bottom of the page.

9. Code

Inline Code

Use `code` to mark inline code.

Code Blocks

Use three backticks to create code blocks, optionally specifying a language for syntax highlighting.

```python
def hello_world():
    print("Hello, World!")
```

10. Lists

Unordered Lists

- Item One
- Item Two
  - Subitem One
  - Subitem Two
- Item Three

Ordered Lists

First Item
Second Item
Subitem One
Subitem Two
Third Item

11. Liquid Template Syntax

Jekyll supports the Liquid templating language, which can be used within Markdown.

Current Year: 2026

Site Title: Your awesome title

Page URL: /2026/09/05/blog.html

Common Liquid Filters:

| date: "%Y": Format date
| downcase: Convert to lowercase
| upcase: Convert to uppercase
| strip_html: Remove HTML tags
| markdownify: Convert Markdown to HTML

12. Callouts

The Just the Docs theme provides special callout syntax.

{: .note }
This is a note callout.

{: .warning }
> This is a warning callout, often combined with blockquotes.

Available Callout Types:

.note: Regular note
.warning: Warning
.important: Important note
.new: New content note

13. Tables

| Header 1 | Header 2 | Header 3 |
|----------|----------|----------|
| Cell 1   | Cell 2   | Cell 3   |
| Cell 4   | Cell 5   | Cell 6   |

14. Task Lists

- [x] Completed Task
- [ ] Incomplete Task
- [ ] Another Incomplete Task

15. Definition Lists

Term One
: Definition One

Term Two
: Definition Two
: Second Definition

Best Practices

Maintain Consistency: Use the same Markdown style throughout the website
Use Front Matter Appropriately: Set appropriate title, description, and navigation order for each page
Use Attribute Blocks Reasonably: Utilize CSS classes provided by the theme to enhance visual effects
Semantic Markup: Use correct heading levels (don’t skip levels)
Accessibility: Add alt text for images, provide meaningful text for links

References

Clash

2026-09-05T00:00:00+00:00

Clash

Introduction

clash is a tunnel in Go.

Installation

openSUSE contains clash in its repository, so it can be downloaded directly

sudo zypper in clash

Debian repository does not contain clash, so it can be downloaded from Github release. It also can be downloaded in command. As an example

wget https://github.com/Dreamacro/clash/releases/download/v1.18.0/clash-linux-amd64-v1.18.0.gz mv clash-linux-amd64-v1.18.0.gz clash

Basic Usage

If clash is run in the user space, copy the config.yaml file to ~/.config/clash/ directory and run

clash

Clash will download the Country.mmdb file by itselef and load the configuration in ~/.config/clash/.

Autostart

Clash support auto-start after opening the system. In openSUSE, the download version of clash has a systemd service with /lib/system/system/clash.service to support the auto-start process. This service is based on systemd, so it works for openSUSE and other distributions that uses systemd as the init process. Different from manually run clash, the systemd will load the configuration in the directory /etc/clash/ by default. So move the configuration file and mmdb file in the above directory by

sudo mv /path/to/config/file /etc/clash/ sudo mv /path/to/Country.mmdb /etc/clash

Then, enable and start clash service

systemclt enable clash systemclt start clash

The final process is to config the system-level network setting or program-level network setting to use the clash service.

Clash for LAN

Clash can support connection from devices in the local area network (LAN). To enable it, just edit the config.yaml file and set the allow-lan to true. Then open clash with manual

clash -d ~/.config/clash/

Desktop Environment

2026-09-05T00:00:00+00:00

Desktop Environment

A Linux distribution usually has two types of interfaces. One of them is virtual console (CLI) and the other is GUI. Virtual console is the default interface from Linux kernel and does not support Unicode. For example, in Debian/Ubuntu, type ++F@{1-6@} can change between virtual console and GUI. Specifically, ++F2 can change to the GUI, and ++F@{3,4,5,6@} are different virtual consoles. Desktop environment is a collection of GUI programs that replaces CLI and is one of the most complicated subsystem in Linux. It breaks up the limitation of shell and provides a more flexiable interface for users. By default, the startup program, i.e., systemd, will initialize the GUI desktop. The desktop also can be opened manually. For example, sudo startx is the command to start an x11 service. x11 and Wayland are two communication protocol that relates a display server and the client. Most of the desktop and libraries are based on them.

Graphicless compares the follow open-source desktop environments.

@multitable @columnfractions .2 .2 .2 .2 .2 @headitem @tab KDE @tab GNOME @tab xfce @tab LXQT
@item Toolkit @tab QT @tab GTK @tab GTK @tab QT
@item Display manager @tab SDDM @tab gdm @tab LightDM @tab SDDM
@item Session manager @tab ksmserver @tab gnome-session @tab xfce4-session @tab lxqt-session @item Windows manager @tab KWin @tab gnome-shell @tab xfwm4 @tab Openbox
@item Desktop manager @tab - @tab - @tab xfdesktop @tab -
@item File manager @tab Dolphin @tab Nautilus @tab Thunar @tab PcManFm-qt
@item Launcher @tab Kickoff @tab - @tab xfce-panel @tab lxqt-runner @item Editor @tab Kate @tab gnome-text-editor @tab Mousepad @tab -
@item Terminal @tab Konsole @tab gnome-terminal @tab xfce4-terminal @tab QTerminal
@item Network @tab Network Manager @tab Network Manager @tab - @tab -
@item Capturer @tab Spectacle @tab GNOME Screenshot @tab xfce4-screenshooter @tab Screengrab
@item Document viewer @tab Okular @tab Evince @tab - @tab -
@item Image viewer @tab Gwenview @tab Loupe @tab Ristretto @tab Lximage-qt
@item Input method @tab - @tab - @tab - @tab -
@item Advanced setting @tab - @tab gnome-tweaks @tab - @tab -
@item Development @tab KDevelop @tab GNOME Builder @tab - @tab -
@end multitable

GNOME

Advanced Setting

gnome-tweaks gives advanced settings for gnome. It support swap of Caplock and Ctrl. Download it in Debian with

sudo apt install gnome-tweaks

This swap is only useful in gnome-based GUI. Windows has a similar tool that named as PowerToys.

xfce4

Graphicless tests xfce4 in Debian 12. It uses xfce4-terminal and firefox as the default applications for terminal and web browser, respectively.

Window Manager

@multitable @columnfractions .2 .2 .2 .2 .2 @headitem @tab Openbox @tab i3 @tab xmonad @tab sway @item Protocol @tab x11 @tab x11 @tab Wayland @tab Wayland @end multitable

Openbox

Install Openbox with apt

sudo apt install openbox

By default, openbox has a refresh issue in Ubuntu. The applications will not automatic refresh after opening them. To fix this, change the configuration file

sudo vim /usr/lib/x86_64-linux-gnu/openbox-autostart

Uncommand the line test -z $BG || $BG -solid "#303030"

tmux

Tmux is a famous terminal multiplexer. It works like a window manager in terminal. This is only part of the common keys and commands for tmux. To read the full list, use man tmux or type + ?. The keybindings are in the “DEFAULT KEY BINDINGS” section.

is the default prefix key of tmux. The follow shortcuts omit the prefix key.

Normal mode

@example # Session d # Detach the window from the session s # Select a new session (/) # Move to the previous/next session

tmux ls/list                            # List sessions
tmux attach/detach                      # Attach/Detach the window to the session
tmux kill-session -t      # Close (Kill) the session

# Window
c       # Create new window
l       # Toggle last active window
n/p     # Next/Previous window
w       # List windows

tmux new -s               # Create a new window for the session

# Pane
o             # Go to next pane
q        # Switch to the pane
x             # Close the pane
z             # Toggle pane zoom
@{ or @}      # Move the pane to left/right
% or "        # Split pane with vertical/horizontal
///          # Go to the up/down/left/right pane

@end example

Copy mode

In copy mode, user can view the contents in tmux pane. The user also can use vim-like commands to view and copy the content. @example [ # Enter copy mode. @end example

Command line mode

The follow key does not need prefix key.

@example : # Enter command-line mode @end example

Distribution

2026-09-05T00:00:00+00:00

Distribution

Linux contains lots of well-known distributions. A Linux distribtuion comprises multiple drivers to support different hardware architectures and a collections of softwares in the user sapce. The follow tables summarize the main different between these awesome distributions and the programs.

@multitable @columnfractions .18 .16 .16 .16 .16 .16 @headitem @tab Arch @tab Debian @tab Fedora @tab NixOS @tab Void
@item Init system @tab systemd @tab systemd @tab systemd @tab systemd @tab runit
@item Package manager @tab pacman @tab apt @tab dnf @tab Nix @tab xbps
@item C library @tab glibc @tab glibc @tab glibc @tab glibc @tab musl
@item Utility @tab coreutils @tab coreutils @tab coreutils @tab coreutils @tab coreutils @item Installer @tab CLI @tab Debian-Installer @tab Anaconda @tab Calamares @tab CLI
@end multitable

The distributions for embeded devices

@multitable @columnfractions .2 .2 .2 .2 .2 @headitem @tab Openwrt @tab Alpine
@item Init system @tab init @tab OpenRC @item Package manager @tab opkg @tab apk
@item Utility @tab Busybox @tab Busybox
@end multitable

Package Manager

The follow lists common package managers that in different distributions. @itemize @bullet @item apt @item dnf @item pacman @item zypper @item Flatpak @item AppImage @end itemize

dnf

dnf or Dandified YUM is the next-generation of the Fedora package manger yum. It manages rpm packages.

COPR is an extra repository for Fedora. NeuroFedora team move the softwares to official Fedora repositories. Add this repo into the dnf repo list by running sudo dnf copr enable @@neurofedora/neurofedora-extra

The source files of an rpm package are in the *.src.rpm.

@example

Download the src.rpm

dnf download –source

List the infomation in the *src.rpm

rpm -ql *.src.rpm

Extract the *src.rpm

rpm2cpio *.src.rpm | cpio -idv

Install source code from *src.rpm to home directory

rpm -i *src.rpm

Rebuild the source package if it is patched

rpmbuild -bb /spec/directory/package.spec @end example

The default directory for the rpm macros is under/usr/lib/rpm/macros.

zypper

openSUSE uses zypper as the default package manager. It is based on RPM, which is similar to Fedora. zypper uses repository for packages. zypper repos lists repositories. Search all installed packages in a target repo, use zypper search -i -r .

Besides installation of the built programs, zypper also provides an official repository for the source code. As an example, the download and build process for the hostapd is

@example sudo zypper source-install hostapd # or sudo zypper si hostapd cd /usr/src/packages/ # cd to the default directory for source code ls SOURCES ls SPECS sudo zypper in rpmbuild # The build tool of the download source code sudo rpmbuild -ba SPECS/hostapd.spec # -ba means to perform a full build. ls RPMS/x86_64 # The built program in the x86 architecture sudo rpmbuild -ba –noclean SPECS/hostapd.spec # It does not remove the extracted source code ls BUILD # The extracted source code @end example

openSUSE also provides a command-line tool for package download, building and packaging. The name of the tool is osc, which means openSUSE commander. To use it, run

sudo zypper install osc

Flatpak

Flatpak is a cross-platform package manager that run applications in a sandbox. It can download apps from FlatHub, which is the official repository of Flatpak.

flatpak install

Different from apt/zypper/dnf/pacman, you cannot run the applications from flatpak directly.

flatpak run

Init Process

In Linux, the first process is usually init or systemd. They both work to manage the initialization of the system before the login shell. The PID of them is 1, which means the first process after the kernel.

System V and init

init is the initial script in System V project. In a early version of a Linux distribution, it usually uses init as the initalization system. It finds the configuration file in /etc/inittab and runs the scripts in /etc/rc according to the runlevel. Different runlevels means different modes of init. It will run the corresponding runlevel scripts in /etc/rcN.d/, where N means the runlevel. The value of N is from 0 to 6. All scripts under these directories are a symbolic link to a file in etc/init.d/. The file started with “S” means “start it”, while “K” means “kill it”. The feature of init is run all script in a fixed order one-by-one, so it is easy to find the error, while costs lots of time.

systemd

In contrast, systemd concurrently runs all scripts.

In a system that initialized with systemd, the init file, which is /usr/sbin/init will be a symbolic to the /lib/systemd/systemd. The default configuration file of systemd is /usr/lib/systemd/system/default.target, which is also a symbolic link to /usr/lib/systemd/system/graphical.target. You can find the default target with

systemctl get-default

Live CD

This section discribes how to create a custom Live CD in Fedora with livemedia-creator.

@example

Install mock, which provides an independent compose environment.

sudo dnf install mock

Init mock

mock -r --init

Install packages into the composed environment

mock -r --install lorax-lmc-novirt vim-minimal pykickstart livecd-tools

chroot into the environment

mock -r

After that, the user has been changed into the compose environment, and the packages for composion have been installed. The next step is get the configuration files for the target ISO. These files are named as kickstart files, and .ks is the file extension. The kickstart files are in the fedora kickstarts project. Download the files and move it into the mock environment.

The home directory of is under the `/var/lib/mock//root/builddir`. The project can be directly copied into the builddir of the compose environment. Another method is to copy the project with the command

mock -r --copyin /builddir

The kickstart files in the project are templates, it should be resolved by flattening in the compose environment.

ksflatten --config -o flat-

In X64 system, compose the Fedora 42 system lacks shim-ia32 package. It should be installed manually. To do that, add the package name, i.e. shim-ia32 after the %packages in the flatten kickstart file.

Finally, run the livemedia-creator

livemedia-creator --ks flat-

Your awesome title

Welcome to Jekyll!

Blog

Blog

Installation

Jekyll Themes

Usage

Upgrade

Jekyll Syntax

1. Front Matter (YAML Header)

2. Headings

3. Attribute Blocks

4. Horizontal Rules

5. Blockquotes

6. Links

Basic Links

Links with Titles

Reference-style Links

7. Emphasis

Italic

Bold

Bold and Italic

8. Footnotes

9. Code

Inline Code

Code Blocks

10. Lists

Unordered Lists

Ordered Lists

11. Liquid Template Syntax

12. Callouts

13. Tables

14. Task Lists

15. Definition Lists

Best Practices

References

Clash

Clash

Introduction

Installation

Basic Usage

Autostart

Clash for LAN

Desktop Environment

Desktop Environment

GNOME

Advanced Setting

xfce4

Window Manager

Openbox

tmux

Normal mode

Copy mode

Command line mode

Distribution

Distribution

Package Manager

dnf

Download the src.rpm

List the infomation in the *src.rpm

Extract the *src.rpm

Install source code from *src.rpm to home directory

Rebuild the source package if it is patched

zypper

Flatpak

Init Process

System V and init

systemd

Live CD

Install mock, which provides an independent compose environment.

Init mock

Install packages into the composed environment

chroot into the environment

Linux To Go

Editor

Editor

Vim

Normal/Visual Mode

Input Method

Input Method