Mitja Felicijan's notes

60's IBM Computers Commercial

Thu, 29 Jun 2023 22:13:45 +0200

Likely aired during an hour-long program during the 1960s, long commercials such +as this typically aired during hour-long programs. They would not have aired +during a half-hour program.

10/GUI 10 Finger Multitouch User Interface

Thu, 29 Jun 2023 14:51:39 +0200

Message from 10/GUI team (page 10gui.com does not exist anymore):

Over a quarter-century ago, Xerox introduced the modern graphical user +interface paradigm we today take for granted.

That it has endured is a testament to the genius of its design. But the +industry is now at a crossroads: New technologies promise higher-bandwidth +interaction, but have yet to find a truly viable implementation.

10/GUI aims to bridge this gap by rethinking the desktop to leverage technology +in an intuitive and powerful way.

Alacritty open links with modifier

Sun, 25 Jun 2023 17:17:16 +0200

Alacritty by default makes all links in the terminal output clickable and this +gets annoying rather quickly. I liked the default behavior of Gnome terminal +where you needed to hold Control key and then you could click and open links.

To achieve this in Alacritty you need to provide a hint in the configuration +file. Config file is located at ~/.config/alacritty/alacritty.yml.

hints:
+  enabled:
+  - regex: "(mailto:|gemini:|gopher:|https:|http:|news:|file:|git:|ssh:|ftp:)\
+            [^\u0000-\u001F\u007F-\u009F<>\"\\s{-}\\^⟨⟩`]+"
+    command: xdg-open
+    post_processing: true
+    mouse:
+      enabled: true
+      mods: Control
+

The following should work under any Linux system. For macOS, you will need to +change command: xdg-open to something else.

Now the links will be visible and clickable only when Control key is being +pressed.

Source: https://github.com/alacritty/alacritty/issues/5246

Development environments with Nix

Sun, 25 Jun 2023 16:38:10 +0200

Nix is amazing for making reproducible cross OS development environment.

First you need to install Nix package +manager.

Create a file shell.nix in your project folder.
In the section that has python3 etc add programs you want to use. These can +be CLI or GUI applications. It doesn't matter to Nix.

{ pkgs ? import <nixpkgs> {} }:
+  pkgs.mkShell {
+    nativeBuildInputs = with pkgs.buildPackages; [
+	  python3
+	  tinycc
+	];
+}
+

And then run it nix-shell. By default it will look for shell.nix file. If +you want to specify a different file use nix-shell file.nix. That is about it.

When the shell is spawned it could happen that your PS1 prompt will be +overwritten and your prompt will look differently. In that case you need to +either do NIX_SHELL_PRESERVE_PROMPT=1 nix shell or add +NIX_SHELL_PRESERVE_PROMPT variable to your bashrc or zshrc file and set it +to 1.

I also have a modified PS1 prompt for Bash that I use and it also catches the +usage of Nix shell.

NIX_SHELL_PRESERVE_PROMPT=1
+
+parse_git_branch() {
+	git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
+}
+
+is_inside_nix_shell() {
+	nix_shell_name="$(basename "$IN_NIX_SHELL" 2>/dev/null)"
+	if [[ -n "$nix_shell_name" ]]; then
+		echo " \e[0;36m(nix-shell)\e[0m"
+	fi
+}
+
+export PS1="[\033[38;5;9m\]\u@\h\[$(tput sgr0)\]]$(is_inside_nix_shell)\[\033[33m\]\$(parse_git_branch)\[\033[00m\] \w\[$(tput sgr0)\] \n$ "
+

And this is what it looks like when you are in a Nix shell. Otherwise that part +of prompt is omitted

More resources:

Making cgit look nicer

Sat, 24 Jun 2023 13:33:58 +0200

For personal use I have a private Git server +set up and I use GitHub just as a mirror. By default the cgit theme looks a bit +dated so I made the flowing theme.

/etc/cgitrc

css=/cgit.css
+logo=/startrek.gif
+favicon=/favicon.png
+source-filter=/usr/lib/cgit/filters/syntax-highlighting-edited.sh
+about-filter=/usr/lib/cgit/filters/about-formatting.sh
+
+local-time=1
+snapshots=tar.gz
+repository-sort=age
+cache-size=1000
+branch-sort=age
+summary-log=200
+max-atom-items=50
+max-repo-count=100
+
+enable-index-owner=0
+enable-follow-links=1
+enable-log-filecount=1
+enable-log-linecount=1
+
+root-title=Place for code, experiments and other bullshit!
+root-desc=
+clone-url=git@git.mitjafelicijan.com:/home/git/$CGIT_REPO_URL
+
+mimetype.gif=image/gif
+mimetype.html=text/html
+mimetype.jpg=image/jpeg
+mimetype.jpeg=image/jpeg
+mimetype.pdf=application/pdf
+mimetype.png=image/png
+mimetype.svg=image/svg+xml
+
+readme=:README.md
+readme=:readme.md
+
+# Must be at the end!
+virtual-root=/
+scan-path=/home/git/
+

For syntax-highlighting-edited.sh follow instructions on +https://wiki.archlinux.org/title/Cgit.

/usr/share/cgit/cgit.css

* {
+        font-size: 11pt;
+}
+
+body {
+        font-family: monospace;
+        background: white;
+        padding: 1em;
+}
+
+th, td {
+        text-align: left;
+}
+
+/* HEADER */
+
+#header {
+        margin-bottom: 1em;
+}
+
+#header .logo img {
+        display: block;
+        height: 3em;
+        margin-right: 10px;
+}
+
+#header .sub.right {
+        display: none;
+}
+
+/* FOOTER */
+
+.footer {
+        margin-top: 2em;
+        font-style: italic;
+}
+
+.footer, .footer a {
+        color: gray;
+}
+
+/* TABS */
+
+.tabs a {
+        margin-bottom: 2em;
+        display: inline-block;
+        margin-right: 1em;
+}
+
+.tabs td a:only-child {
+        display: none;
+}
+
+/* HIDING ELEMENTS */
+
+.cgit-panel, .form {
+        display: none;
+}
+
+/* LISTS */
+
+.list td, .list th {
+        padding-right: 2em;
+}
+
+.list .nohover a {
+        color: black;
+}
+
+.list .button {
+        padding-right: 0.5em;
+}
+
+/* COMMIT */
+
+.commit-subject {
+        padding: 1em 0;
+}
+
+.decoration a {
+        padding-left: 0.5em;
+}
+
+.commit-info th {
+        padding-right: 1em;
+}
+
+.commit-subject {
+        padding: 2em 0;
+}
+
+table.diff div.head {
+        padding-top: 2em;
+}
+
+table.diffstat td {
+        padding-right: 1em;
+}
+
+/* CONTENT */
+
+.linenumbers {
+        padding-right: 0.5em;
+}
+
+.linenumbers a {
+        color: gray;
+}
+
+.pager {
+        display: flex;
+        list-style-type: none;
+        padding: 0;
+        gap: 0.5em;
+}
+
+/* DIFF COLORS */
+
+table.diff {
+        width: 100%;
+}
+
+table.diff td {
+        white-space: pre;
+}
+
+table.diff td div.head {
+        font-weight: bold;
+        margin-top: 1em;
+        color: black;
+}
+
+table.diff td div.hunk {
+        color: #009;
+}
+
+table.diff td div.add {
+        color: green;
+}
+
+table.diff td div.del {
+        color: red;
+}
+

Simple presentations with Markdown

Wed, 21 Jun 2023 08:54:48 +0200

A simple way to make presentations without using desktop apps or using online +services is https://github.com/remarkjs/remark.

First create index.html and be sure you make changes to config variable.

<!DOCTYPE html>
+<html>
+
+<head>
+    <title></title>
+    <meta charset="utf-8">
+    <style>
+        body {
+            font-family: 'SF Pro Display';
+        }
+
+        .remark-code,
+        .remark-inline-code {
+            font-family: 'SF Mono';
+            font-size: medium;
+            background-color: gainsboro;
+            border-radius: 5px;
+            padding: 0 5px;
+        }
+    </style>
+</head>
+
+<body>
+    <textarea id="source"></textarea>
+    <script src="https://remarkjs.com/downloads/remark-latest.min.js"></script>
+    <script>
+		const config = {
+			title: 'My presentation',
+			file: 'presentation.md',
+		};
+	
+		document.title = config.title;
+        remark.create({ sourceUrl: config.file });
+    </script>
+</body>
+
+</html>
+

Now the markdown file presentation.md with presenetation. --- is used to +separate slides. Other stuff is just pure markdown.

class: center, middle
+
+# Main title of the presentation
+
+---
+
+# Fist slide
+
+Eveniet mollitia nemo architecto rerum aut iure iste. Sit nihil nobis libero iusto fugit nam laudantium ut. Dignissimos corrupti laudantium nisi.
+
+- Lorem ipsum dolor sit amet, consectetur adipiscing elit.
+- Integer aliquet mauris a felis fringilla, ut congue massa finibus.
+
+---
+
+# Slide two
+
+- Lorem ipsum dolor sit amet, consectetur adipiscing elit.
+- Vestibulum eget leo ac dolor venenatis pulvinar.
+

Bulk thumbnails

Sun, 04 Jun 2023 20:46:56 +0200

Make bulk thumbnails of JPGs with ImageMagick.

#!/bin/bash
+
+directory="./images/"
+dimensions="360x360"
+
+for file in "$directory"*.jpg; do
+  convert "$file" -resize $dimensions "$file" "${file%.*}-thumbnail.jpg"
+done
+

Edsger W. Dijkstra Manuscripts ebook

Thu, 01 Jun 2023 22:47:56 +0200

I love reading the original manuscripts of Edsger W. Dijkstra. They are +available online at the University of Texas at Austin website, but I also found +MOBI version. I converted it into ePub as well.

Downloads:

Sources and credits:

Extending dte editor

Wed, 31 May 2023 08:12:45 +0200

dte is an interesting editor I started +using lately more and more. Since it is using +execvp() it can be easily extended. I +needed comment/uncomment feature so I created a small utility that does this for +me. Code lives on repository dte +extensions but this +utilities can be used for whatever you want. Make sure you have version 1.11 or +above.

Next one will be invoking formatter based on the type of a file.

My config that works for me.

set show-line-numbers true;
+set tab-width 4;
+set case-sensitive-search false;
+
+# Special aliases
+alias m_comment 'exec -s -i line -o buffer -e errmsg ~/.dte/bin/comment'
+alias m_format 'save; exec go fmt .; reload'
+alias m_duplicate 'copy;paste';
+
+# Useful aliases.
+alias m_force_close 'quit -f';
+alias m_reload 'close; open $FILE'
+
+# Key bindings.
+bind M-s save;
+bind M-q m_force_close;
+bind M-z refresh;
+bind C-down blkdown;
+bind C-up blkup;
+bind C-_ m_comment;
+bind M-. m_format;
+bind C-d m_duplicate;
+
+# Syntax highlighting.
+hi preproc magenta;
+hi keyword red;
+hi linenumber blue;
+hi comment cyan;
+

Grep to Less that maintain colors

Mon, 29 May 2023 21:27:07 +0200

I often use grep to search for todo's in my code and other people's code and +then pipe them in less and I missed having colors that grep outputs in less.

Grep's --color=always use markers to highlight the matching strings.
Less's -R option outputs "raw" control characters.

You could use alias grep='grep --color=always' and alias less='less -R' or +create todo function in your .bashrc that accepts first argument as search +string.

# This is where the magic happens.
+grep --color=always -rni "TODO:" | less -R
+

Easy measure time took in a bash script

Sun, 28 May 2023 17:53:20 +0200

In Bash, the $SECONDS variable is a special variable that automatically keeps +track of the number of seconds since the current shell or script started +executing. It starts counting from the moment the script begins running.

#!/bin/bash
+
+# Reset the timer to zero.
+SECONDS=0
+
+# Do something.
+sleep 5
+
+# Print the time elapsed.
+echo "Time taken: $SECONDS seconds"
+

Make DCSS playable on 4k displays

Sat, 27 May 2023 19:35:11 +0200

Dungeon Crawl Stone Soup has a a very small font by default. On a 4k display, it +is barely readable. This is how I made it playable.

Make a file ~/.crawlrc with the following content:

# Adjust the sizes to your liking.
+
+tile_font_crt_size = 32
+tile_font_stat_size = 32
+tile_font_msg_size = 32
+tile_font_tip_size = 32
+tile_font_lbl_size = 32
+tile_sidebar_pixels = 64
+

To zoom in and out in viewport, press Ctrl+ and Ctrl- respectively.

All the possible options are documented in the Dungeon Crawl Stone Soup Options +Guide +file.

Drawing Pixels in Plan9

Sat, 27 May 2023 17:41:33 +0200

I have started exploring Plan9's graphics capabilities. This is a hello world +alternative for drawing that draws a yellow square on a blue background.

More information:

draw.h header file +contains all the drawing functions
draw man page +has a bit more digestable descriptions of the draw functions
graphics man page +has a bit more digestable descriptions of the graphics functions
all man pages +can be a valuable resource for learning about the system

// main.c
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <cursor.h>
+
+void
+main()
+{
+  ulong co;
+  Image *im, *bg;
+  co = 0x0000FFFF;
+
+  if (initdraw(nil, nil, argv0) < 0)
+  {
+    sysfatal("%s: %r", argv0);
+  }
+
+  im = allocimage(display, Rect(0, 0, 300, 300), RGB24, 0, DYellow);
+  bg = allocimage(display, Rect(0, 0, 1, 1), RGB24, 1, co);
+
+  if (im == nil || bg == nil)
+  {
+    sysfatal("not enough memory");
+  }
+
+  draw(screen, screen->r, bg, nil, ZP);
+  draw(screen, screen->r, im, nil, Pt(-40, -40));
+
+  flushimage(display, Refnone);
+
+  // Wait 10 seconds before exiting.
+  sleep(10000);
+
+  exits(nil);
+}
+

And then compile with mk (mkfile below):

# mkfile
+</$objtype/mkfile
+
+RC=/rc/bin
+BIN=/$objtype/bin
+MAN=/sys/man
+
+main:
+	$CC $CFLAGS main.c
+	$LD $LDFLAGS -o main main.$O
+

And run with ./main. To exit the program, press Delete key (strange but this +is the alternative for Ctrl+C).

This is very cool indeed!

Cronjobs on Github with Github Actions

Sat, 27 May 2023 00:35:36 +0200

In the root of your repository create a folder .github/workflows and in that +folder create a file a file cron.yaml. This file can be named whatever you +wish. But it has to be a yaml file.

File below (.github/workflows/cron.yaml) describes an action that will trigger +every six hours and it will curl example.com.

However. Be sure that you have enough credits. Free account is not that generous +with the minutes they give you for free. Check more about GitHub Actions usage +on their website https://docs.github.com/en/actions.

# .github/workflows/cron.yaml
+name: Do a curl every 6 hours
+on:
+  schedule:
+    - cron: '0 */6 * * *'
+jobs:
+  cron:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Call some url
+        run: curl 'https://example.com'
+

Dungeon Crawl Stone Soup - New player guide

Thu, 25 May 2023 22:00:00 +0200

An amazing game deserves an amazing guide. All this material can be find in some +form on another on craw's official repository.

DCSS Quickstart - Very short introduction to the +game
DCSS Manual - Extensive manual about the game

Movement and Exploration

You can move around with the numpad (try numlock on and off), vi-keys, or +clicking with the mouse. Arrow keys work, though you can't move diagonally +with them. Pressing Shift and a direction will move until you see/hit +something.
Pressing > will take you down a staircase, and < to go up a staircase.
You can open doors by walking into them, and close them with C.
You can autoexplore by pressing o.
You can re-view recent messages with Ctrl-p.

Monsters and Combat

You can pick up items with , or g.
Wield weapons with w. Weapons have different stats. +
- (You may also engage in Unarmed Combat, though it isn't very effective when +untrained).
+
Attack monsters in melee by walking in their direction (or with +Ctrl-direction).
You can wait with . or s, passing your turn - such as to get monsters into +a corridor with you.
You can rest with 5, waiting until you are fully healed, or something +noteworthy happens.
Either mouseover and rightclick, or use x then v on the monster to examine +monsters. Monsters with a red border are 'dangerous' relative to your current +XP level (XL).
Quiver (often ranged) actions for further use with Q.
You can fire ranged weapons manually with f, or auto-target your quiver with +p or Shift-Tab. Throwing weapons can be thrown immediately, while +launchers (like bows) need to be wielded first.

Items and Inventory

View your inventory by pressing i. Most item related commands can also be +done with this menu.
You can wear amour with W; amour gives AC, while heavier body armour +reduces EV.
Autoexplore will automatically pick up useful items, such as potions and +scrolls, if you aren't in danger.
You can read scrolls with r and drink ("quaff") potions with q.
Equipment items may have brands, with special properties. Branded equipment is +blue when unidentified.
Equipment items may be artifacts, often with unique properties, and are +unmodifiable. They are written in white.
You can evoke wands with V.
You can put on jewelry with P, and remove it with R.
Gold is used in shops, which can be interacted with by either > or <.

Magic and Spellcasting

Once you find a spellbook, you can memorize spells with M.
You need to be the same XL as the spell's spell level in order to learn it, in +addition to training magical skill (to lower failure rate).
Cast spells by pressing z, then the letter assigned to the spell. You may +also Quiver a spell and then use it like a ranged weapon (with Shift-Tab).
You can view your memorized spells by pressing I (capital-i) or z.
Like HP, you can recover MP by resting (with 5).
Many spells can be positioned more effectively, or combined with other spells, +in order to get (more effective) use out of them.
Heavier body amour and shields hamper spellcasting.

Gods and Divine Abilities

You may look at a god's overview by praying at their altar (with > or <). +After praying, you can worship the god by pressing Enter afterwards.
Gods all have unique features about them. Trog, the god of the tutorial, is +also the god of rage and bloodshed, and so despises spellcasting.
Gods like and dislike different things. Most gods either like killing things +(like Trog) or exploring new areas (like Elyvilon), rewarding you piety +(divine favor) for doing so.
You should learn to use and even rely on divine abilities often, as they are +usually very strong. Trog's Berserk gives you 1.5x health, 1.5x speed (to all +valid actions), and a big damage boost. Note that Berserk prevents most +actions other than move and melee attack, and runs out very quickly if you +aren't attacking. And after berserk ends, you are slowed down and can't +berserk again for a short time.
In addition, the vast majority of abilities consume piety in the process. +Regardless, this ability is very cheap, and the benefits are incredible, so +don't hold back!
Pressing ^ will let you view your current god, abilities, and piety.

Display xterm color palette

Thu, 25 May 2023 12:00:00 +0200

bash xterm-palette.sh - will show you number of max colors available
bash xterm-palette.sh -v - will create a list of all colors with codes

#!/usr/bin/env bash
+# xterm-palette.sh
+
+trap 'tput sgr0' exit		# Clean up even if user hits ^C
+
+function setfg () {
+    printf '\e[38;5;%dm' $1
+}
+
+function setbg () {
+    printf '\e[48;5;%dm' $1
+}
+
+function showcolors() {
+    # Given an integer, display that many colors
+    for ((i=0; i<$1; i++))
+    do
+	printf '%4d ' $i
+	setbg $i
+	tput el
+	tput sgr0
+	echo
+    done
+    tput sgr0 el
+}
+
+# First, test if terminal supports OSC 4 at all.
+printf '\e]4;%d;?\a' 0
+read -d $'\a' -s -t 0.1 </dev/tty
+if [ -z "$REPLY" ]
+then
+    # OSC 4 not supported, so we'll fall back to terminfo
+    max=$(tput colors)
+else
+    # OSC 4 is supported, so use it for a binary search
+    min=0
+    max=256
+    while [[ $((min+1)) -lt $max ]]
+    do
+	i=$(( (min+max)/2 ))
+	printf '\e]4;%d;?\a' $i
+	read -d $'\a' -s -t 0.1 </dev/tty
+	if [ -z "$REPLY" ]
+	then
+            max=$i
+	else
+	    min=$i
+	fi
+    done
+fi
+
+
+# If -v is given, show all the colors
+case ${1-none} in
+    none)
+	echo $max
+	;;
+    -v)
+	showcolors $max
+	;;
+    *)
+	if [[ "$1" -gt 0 ]]; then
+	    showcolors $1
+	else
+	    echo $max
+	fi
+	;;
+esac | less --raw-control-chars --QUIT-AT-EOF --no-init
+

Sane defaults for tmux with more visible statusbar

Thu, 25 May 2023 12:00:00 +0200

# Remap prefix from 'C-b' to 'M-a'.
+unbind C-b
+set-option -g prefix M-a
+bind-key M-a send-prefix
+
+# Split panes using | and -.
+bind | split-window -h
+bind - split-window -v
+unbind '"'
+unbind %
+
+# Start counting windows with 1.
+set-option -g allow-rename on
+set -g base-index 1
+setw -g pane-base-index 1
+
+# Statusbar: purple bg and white fg.
+set -g status-bg '#480b8e'
+set -g status-fg '#ffffff'
+
+# Active window: black bg and white fg. 
+set -g window-status-current-format "#[fg=#ffffff]#[bg=#111111]#[fg=#ffffff]#[bg=#111111] #I:#W #[fg=#ffffff]#[bg=#111111]"
+
+# Disable mouse mode (tmux 2.1 and above).
+set -g mouse off
+

My brand new Plan9/9front desktop

Wed, 24 May 2023 12:00:00 +0200

I have been experimenting with Plan9/9front for a week now. Noice! This is how +my desktop looks like.

Parse RSS feeds with Lua

Tue, 23 May 2023 12:00:00 +0200

Example of parsing RSS feeds with Lua. Before running the script install:

feedparser with luarocks install feedparser
luasocket with luarocks install luasocket

local http = require("socket.http")
+local feedparser = require("feedparser")
+
+local feed_url = "https://mitjafelicijan.com/feed.rss"
+
+local response, status, _ = http.request(feed_url)
+if status == 200 then
+  local parsed = feedparser.parse(response)
+
+  -- Print out feed details.
+  print("> Title   ", parsed.feed.title)
+  print("> Author  ", parsed.feed.author)
+  print("> ID      ", parsed.feed.id)
+  print("> Entries ", #parsed.entries)
+
+  for _, item in ipairs(parsed.entries) do
+    print("GUID    ", item.guid)
+    print("Title   ", item.title)
+    print("Link    ", item.link)
+    print("Summary ", item.summary)
+  end
+else
+  print("! Request failed. Status:", status)
+end
+

Extend Lua with custom C functions using Clang

Tue, 23 May 2023 12:00:00 +0200

Here is a boilerplate for extending Lua with custom C functions. This requires +Clang and Lua 5.1 to be installed. GCC can be used instead of Clang, but the +Makefile will need to be modified.

nativefunc.c

#include <lua.h>
+#include <lauxlib.h>
+
+static int l_mult50(lua_State *L) {
+  double number = luaL_checknumber(L, 1);
+  lua_pushnumber(L, number * 50);
+  return 1;
+}
+
+int luaopen_nativefunc(lua_State *L) {
+  static const struct luaL_Reg nativeFuncLib[] = {{"mult50", l_mult50}, {NULL, NULL}};
+
+  luaL_register(L, "nativelib", nativeFuncLib);
+  return 1;
+}
+

main.lua

require "nativefunc"
+print(nativelib.mult50(50))
+

Makefile

CC       = clang
+CFLAGS   =
+INCLUDES = `pkg-config lua5.1 --cflags-only-I`
+
+all:
+  $(CC) -shared -o nativefunc.so -fPIC nativefunc.c $(CFLAGS) $(INCLUDES)
+
+clean:
+  rm *.so
+

Execute not blocking async shell command in C#

Mon, 22 May 2023 12:00:00 +0200

Execute a shell command in async in C# while not blocking the UI thread.

private async Task executeCopyCommand()
+{
+  await Task.Run(() =>
+  {
+    var processStartInfo = new ProcessStartInfo("cmd", "/c dir")
+    {
+      RedirectStandardOutput = true,
+      UseShellExecute = false,
+      CreateNoWindow = true
+    };
+
+    var process = new Process
+    {
+      StartInfo = processStartInfo
+    };
+
+    process.Start();
+    process.WaitForExit();
+  });
+}
+

Make sure that async is present in the function definition and await is used +in the method that calls executeCopyCommand().

private async void button_Click(object sender, EventArgs e)
+{
+  await executeCopyCommand();
+}
+

Change permissions of matching files recursively

Tue, 16 May 2023 12:00:00 +0200

Replace *.xml with your pattern. This will remove executable bit from all +files matching the pattern. Change + to - to add executable bit.

find . -type f -name "*.xml" -exec chmod -x {} +
+

Previews how man page written in Troff will look like

Mon, 15 May 2023 12:00:00 +0200

Troff is used to write man pages and it is difficult to read it so this will +preview how it will look like when it is rendered.

# On Linux system.
+groff -man -Tascii filename
+
+# On Plan9 system.
+man 1 filename
+

Convert all MKV files into other formats

Sun, 14 May 2023 12:00:00 +0200

You will need ffmpeg installed on your system. This will convert all MKV files +into WebM format.

# Convert all MKV files into WebM format.
+find ./ -name '*.mkv' -exec bash -c 'ffmpeg -i "$0" -vcodec libvpx -acodec libvorbis -cpu-used 5 -threads 8 "${0%%.mp4}.webm"' {} \;
+

# Convert all MKV files into MP4 format.
+find ./ -name '*.mkv' -exec bash -c 'ffmpeg -i "$0" c:a copy -c:v copy -cpu-used 5 -threads 8 "${0%%.mp4}.mp4"' {} \;
+

Download list of YouTube files

Sat, 13 May 2023 12:00:00 +0200

If you need to download a list of YouTube videos and don't want to download the +actual YouTube list (which yt-dlp supports), you can use the following method.

// Used to get list of raw URL's from YouTube's video tab'.
+// Copy them into videos.txt.
+document.querySelectorAll('#contents a.ytd-thumbnail.style-scope.ytd-thumbnail').forEach(el => console.log(el.href))
+

Download and install https://github.com/yt-dlp/yt-dlp.

# This will download all videos in videos.txt.
+yt-dlp --batch-file videos.txt -N `nproc` -f webm
+

Install Plan9port on Linux

Fri, 12 May 2023 12:00:00 +0200

Install Plan9port on Linux. This applies to +Plan9port. This is a port of many Plan 9 +programs to Unix-like operating systems. Useful for programs like 9term and +rc.

sudo apt-get install gcc libx11-dev libxt-dev libxext-dev libfontconfig1-dev
+git clone https://github.com/9fans/plan9port $HOME/plan9
+cd $HOME/plan9/plan9port
+./INSTALL -r $HOME/plan9
+

Fix bootloader not being written in Plan9

Thu, 11 May 2023 12:00:00 +0200

If the bootloader is not being written to a disk when installing 9front on real +harware try clearing first sector of the disk with the following command.

dd if=/dev/zero of=/dev/sdX bs=512 count=1
+
+# If command above doesn't work try this one, wait couple of seconds and
+# press delete key to stop the command.
+cat </dev/zero >/dev/sd*/data
+

Take a screenshot in Plan9

Wed, 10 May 2023 12:00:00 +0200

Take a screenshot in Plan9. This applies to Plan9 and +9front. This will take a screenshot of the screen and +output it to /dev/screen. You can then use topng to convert it to a png +image.

# Instant screenshot.
+cat /dev/screen | topng > screen.png
+
+# Delayed screenshot (5 seconds).
+sleep 5; cat /dev/screen | topng > screen.png
+

#cat-v on weechat configuration

Tue, 09 May 2023 12:00:00 +0200

Set up weechat to connect to #cat-v on oftc. This applies to +weechat but should be similar for other irc clients.

# Install weechat and launch it and execute the following commands.
+
+/server add oftc irc.oftc.net -tls
+/set irc.server.oftc.autoconnect on
+/set irc.server.oftc.autojoin "#cat-v"
+/set irc.server.oftc.nicks "nick1,nick2,nick3"
+

Write ISO to USB Key

Mon, 08 May 2023 12:00:00 +0200

Write ISO to USB key. Nothing fancy here.

sudo dd if=iso_file.iso of=/dev/sdX bs=4M status=progress conv=fdatasync
+

Mount Plan9 over network

Sun, 07 May 2023 12:00:00 +0200

First install libfuse with sudo apt install libfuse-dev.
Then clone https://github.com/ftrvxmtrx/9pfs and compile it with make.
Copy 9pfs to your path.

# On Plan9 side
+ip/ipconfig # enables network
+aux/listen1 -tv tcp!*!9999 /bin/exportfs -r tmp # export tmp folder
+
+# On Linux side
+9pfs 172.18.0.1 -p 9999 local_folder # mount
+umount local_folder # unmount
+

Push to multiple origins at once in Git

Sat, 06 May 2023 12:00:00 +0200

Sometimes you want to push to multiple origins at once. This is useful if you +have a mirror of your repository on another server. You can do this by adding +multiple push urls to your git config. This is a shorthand for command above.

git config --global alias.pushall '!sh -c "git remote | xargs -L1 git push --all"'
+

Run 9front in Qemu

Fri, 05 May 2023 12:00:00 +0200

Run 9front in Qemu. This applies to Plan9 and +9front.

Download from here http://9front.org/iso/.

# Create a qcow2 image.
+qemu-img create -f qcow2 $HOME/VM/9front.qcow2.img 30G
+
+# Run the VM.
+qemu-system-x86_64 -cpu host -enable-kvm -m 1024 \
+    -net nic,model=virtio,macaddr=52:54:00:00:EE:03 -net user \
+    -device virtio-scsi-pci,id=scsi \
+    -drive if=none,id=vd0,file=$HOME/VM/9front.qcow2.img \
+    -device scsi-hd,drive=vd0 \
+    -drive if=none,id=vd1,file=$HOME/VM/ISO/9front.386.iso \
+    -device scsi-cd,drive=vd1,bootindex=0
+

Cache busting in Hugo

Mon, 01 May 2023 12:00:00 +0200

{{ $cachebuster := delimit (shuffle (split (md5 "6fab11c6669976d759d2992eff1dd5be") "" )) "" }}
+
+<link rel="stylesheet" href="/style.css?v={{ $cachebuster }}">
+

This 6fab11c6669976d759d2992eff1dd5be can be random string you generate use. +You can use whatever you want.