Linux on The VikiD Truth

Reserve Words

Mon, 22 May 2023 22:02:13 +0400

Reserve Words

Here is the truth about Bash reserved words: they are not commands sitting somewhere in /bin – they are part of the language, recognised before anything is looked up. You cannot name a function if, and type if will tell you why.

What it is, in plain words

Reserved words (keywords) are tokens Bash treats specially when they appear where a command name would. The POSIX set plus Bash extensions includes:

Using Variables in Bash

Mon, 22 May 2023 21:53:51 +0400

BASH | Bash Cookbook |

Using Variables in Bash

Here is the truth about Bash variables: they are all strings, and everything interesting is about when those strings get split, expanded or left alone. Master expansion and the rest of the shell starts to behave.

What it is, in plain words

A variable in Bash is a name bound to a string value (arrays are the structured exception). You assign with =, no spaces:

The i3 Window Manager

Thu, 30 Mar 2023 09:22:22 +0400

The i3 Window Manager

i3 Config File

i3wm:refcard The location of this file is ../home/user/.i3/config.

These are some notes on the i3 config file. It is not the complete file.

# Set the Mod Key
set $mod Mod4

default_border pixel 1
default_floating_border normal
hide_edge_borders none

bindsym $mod+u border none
bindsym $mod+y border pixel 3
bindsym $mod+n border pixel normal

# Font for window tiles. Will also be used by the bar unless a different font
# is used in the bar {} block below.
font xft:URWGothic-Book 11

floating_modifier $mod

bindsym $mod+Return exec alacrity
bindsym $mod+Shift+q kill

bindsym $mod+d exec --no-startup-id dmenu_recency

bindsym $mod+z exec --no-startup-id morc_menu

bindsym XF86MonBightnessUP exec "xbacklight -inc 1; notify-send 'brightness up'"
bimdsym XF86MonBrightnessDown exec "xbacklight -dec 1; notify-send 'brightness down'"

bindsym $mod+Ctrl+b exec terminal -e 'bmenu'
bindsym $mod+F2 exec firefox

# File Managers
bindsym $mod+F3 exec pcmanfm
bindsym $mod+F4 exec ranger
bindsym $mod+Shift+F3 exec pcmanfm_pkexec

# The Console Audio Player
bindsym $mod+F5 exec terminal -e 'mocp'

bindsym $mod+t exec --no-startup-id pkill picom
bindsym $mod+Ctrl+t exec --no-startup-id picom -b

# Notification Daemon
bindsym $mod+Shift+d --release exec "killall dunst; exec notify-send 'restart dunst'"

# Screenshots
bindsym $Print exec --no-startup-id i3-scrot
bindsym $mod+Print -release exec --no-startup-id i3-scrot -w
bindsym $mod+Shift+Print --release exec --no-startup-id i3-scrot -s

bindsym $mod+Shift+h exec xdg-open /usr/share/doc/manjaro/i3_help.pdf

bindsym $mod+Ctrl+x --release exec --no-startup-id xkill

# change focus, move and split
bindsym $mod+j focus left
bindsym $mod+k focus down
bindsym $mod+l focus up
bindsym $mod+semicolon focus right

bindsym $mod+Shift+j move left
bindsym $mod+Shift+k move down
bindsym $mod+Shift+l move up
bindsym $mod+Shift+semicolon move right

workspace_auto_back_and_forth yes
bindsym $mod+b workspace back_and_forth
bindsym $mod+Shift+b move container to workspace back_and_forth; workspace back_and_forth

bindsym $mod+h split h; exec notify-send 'tile horizontally'
bindsym $mod+v split v; exec notify-send 'tile vertically'
bindsym $mod+q split toggle

# toggle fullscreen
bindsym $mod+f fullscreen toggle

bindsym $mod+s layout stacking
bindsym $mod+w layout tabbed
bindsym $mod+e layout toggle split

bindsym $mod+Shift+Space floating toggle

bindsym $mod+space focus mode_toggle
bindsym $mod+Shift+s stick toggle

bindsym $mod+a focus parent

bindsym $mod+Shift+minus move scratchpad

bindsym $mod+Ctrl+Right workspace next
bindsym $mod+Ctrl+Left workspace prev

set $ws1 1:term
set $ws2 2:browser
set $ws3 3:emacs
set $ws4 4:lisp
set $ws5 5:cuis

bindsym $mod+1 workspace $ws1
# etc... etc...

bindsym $mod+Ctrl+1 move container to workspace $ws1
# etc... etc...

bindsym $mod+Shift+1 move container to workspace $ws1; workspace $ws1
# etc... etc...

assign [class="Thunderbird"] $ws1

for_window [title="alsmixer"] floating enable border pixel 1
for_window [class="calamares"] floating enable border normal
for_window [title="i3_help"] floating enable sticky enable border normal
for_window [class="OBlogout"] fullscreen enable
for_window [class="(?i)virtualbox"] floating enable border normal
# etc... etc...

for_window [urgent=latest] focus

bindsym $mod+Shift+c reload
bindsym $mod+Shift+r restart

bindsym $mod+shift+e exec "i3-nagbar -t warning -m 'You pressed the exit shortcut. Do you really want to exit i3? This will end your X session.' -b 'Yes, exit i3' 'i3-msg exit'"

bindsym $mod+0 mode "$mode_system"
mode "$mode_system"{
 bindsym l exec --no-startup-id i3exit lock, mode "default"
 bindsym s exec --no-startup-id i3exit suspend, mode "default"
 bindsym u exec --no-startup-id i3exit switch_user, mode "default"
 bindsym e exec --no-startup-id i3exit logout, mode "default"
 bindsym h exec --no-startup-id i3exit hibernate, mode "default"
 bindsym r exec --no-startup-id i3exit reboot, mode "default"
 bindsym Shift+s exec --no-startup-id i3exit shutdown, mode "default"

 bindsym Return mode "default"
 bindsym Escape mode "default"
}

bindsym $mod+r mode "resize"
mode "resize" {
 bindsym j resize shrink width 5 px or 5 ppt
 bindsym k resize grow height 5 px or 5 ppt
 bindsym l resize shrink height 5 px or 5 ppt
 bindsym semicolon resize grow width 5 px or 5 ppt

 bindsym Left resize shrink width 10 px or 10 ppt
 bindsym Down resize grow height 10 px or 10 ppt
 bindsym Up resize shrink height 10 px or 10 ppt
 bindsym Right resize grow width 10 px or 10 ppt
}

bindsym $mod+9 exec --no-startup-id blurlock

bindsym $mod+m bar mode toggle

Kmonad Keyboard

Wed, 21 Sep 2022 01:43:13 +0400

Kmonad Keyboard

The truth about keyboards is that the layout printed on the keys is just a suggestion. Between the switch and your program sits software that decides what each key means – and KMonad lets you rewrite that decision completely.

What it is, in plain words

KMonad is a keyboard remapper written in Haskell. It grabs your physical keyboard at a low level, runs every key event through a configuration you write, and emits new events through a virtual keyboard. Because it works below the window system, the result works everywhere: in X11, Wayland, the Linux console, even in a login prompt. It runs on Linux, macOS and Windows.

awk

Tue, 06 Sep 2022 12:34:23 +0400

awk

Here is the truth about awk: it is a whole programming language disguised as a command, built for one job – reading text line by line and pulling out the columns you care about. Nearly fifty years on, it still beats writing a script for that job.

What it is, in plain words

awk (named after its authors Aho, Weinberger and Kernighan, Bell Labs, 1977) reads input one record (usually a line) at a time, splits each record into fields (usually on whitespace), and runs your pattern → action rules against it:

xrandr

Tue, 06 Sep 2022 12:14:39 +0400

xrandr

Here is the truth about multi-monitor Linux: the compositor draws, but xrandr decides what exists to draw on. One command can rearrange your whole desk – and a bad one can leave you staring at a black screen, so it’s worth learning carefully.

What it is, in plain words

xrandr (X Resize And Rotate) is the command-line tool for configuring displays under X11: resolution, refresh rate, rotation, and how multiple monitors sit relative to each other. It talks to the X server via the RandR extension. On a laptop it is how you enable an external monitor; on a desktop, how you arrange three screens into one desktop.

Burn an ISO to USB Disk

Tue, 06 Sep 2022 05:52:51 +0400

Burn an ISO to USB Disk

Here is the truth about writing an ISO to a USB stick: the stick becomes the image, byte for byte – it is not a folder you copy files into. Treat it like imaging a disk and you won’t end up with a stick that won’t boot.

Bash case statements

Mon, 29 Aug 2022 00:33:21 +0400

Bash case statements

Here is the truth about case in Bash: it is not a weaker if – it is a pattern matcher, and patterns are where it earns its keep. When you find yourself writing a chain of [[ $x == … ]] branches, case is usually clearer.

Bash - if statements

Mon, 29 Aug 2022 00:28:43 +0400

Bash - if statements

if [ condition ]; then # you can use [[ ]] also
 your code
fi

if [[ "${UID}" -eq 0 ]]
then
 echo 'You are root'
else
 echo 'You are not root'
fi

#!/bin/bash

if [ $(whoami) = 'root' ]; then
	echo "You are root"
fi

In one line:

systemd

Sun, 28 Aug 2022 11:55:25 +0400

systemd

Here is the truth about systemd: it is not “just an init system” – it is a suite that starts the system, supervises services, manages sockets, timers, mounts, devices and logs, and it has largely won. Love it or not, on most Linux boxes in 2026 it is PID 1, and you need to speak its language.

pacman

Tue, 23 Aug 2022 00:11:07 +0400

pacman

pacman -Syu

S stands for sync, y is for refresh (local cache), u is for system update.

pacman -R package_name_ ;to remove a package

To remove a package and its dependencies which are not required by any other installed package:

nmtui

Sun, 22 Aug 2021 04:29:28 +0400

nmtui

Here’s the truth about Linux networking in 2026: you rarely configure interfaces by hand any more – a daemon does it, and you just tell the daemon what you want. On most desktops that daemon is NetworkManager, and nmtui is the friendliest way to talk to it from a terminal.

NCDU

Sun, 22 Aug 2021 04:26:18 +0400

NCDU

The truth about a full disk is that it is almost never “everything, a little bit”. It is usually one or two forgotten directories eating most of the space. ncdu is the tool that points straight at them.

What it is, in plain words

ncdu (NCurses Disk Usage) is a terminal program that scans a directory tree, adds up how much space everything takes, and then lets you walk the result interactively: biggest things at the top, arrow keys to dive in, d to delete. It is du with eyes.

Vikid's Bash Cookbook

Thu, 29 Jun 2017 06:21:51 +0400

BASH | Bash Cookbook |

Vikid’s Bash Cookbook

Some Simple Stuff

bash --version

ls -adFlLQrRS1

pwd -L, pwd -P

type which, type -a which

apropos zip => man -k, locate which

find

stat, file -b

chsh -s /bin/bash

passwd -el

sudo cat /etc/shells

Common Shell Variables

$USER
$- list all current option flags

Download a website

wget -r -np -k http://somesite.com

Options:

-r (recursive)
-np (don’t follow links to parent directories)
-k to make links in downloaded HTML or CSS point to local files
-nd (no directories): download all files to the current directory
-e robots.off: ignore robots.txt files, don’t download robots.txt files
-A png,jpg: accept only files with the extensions png or jpg
-m (mirror): -r –timestamping –level inf –no-remove-listing
-nc, –no-clobber: Skip download if files exist

Quoting

echo value is $3?!
echo "value is $3?!"
echo 'value is $3?!'

!" is history substitution

penti

Tue, 13 Dec 2016 03:15:15 +0400

Penti

Here is a truth about typing that Alexander Burger (the creator of PicoLisp) took seriously: ten fingers on a QWERTY keyboard is not the only way – and for some jobs, not the best way. Penti is his five-finger keyboard layout: one hand, five keys, every character reachable by chords.

What it is, in plain words

Penti is a chorded keyboard system. You rest five fingers of one hand on five keys (by default the home row asdfg or hjkl;), and you type by pressing combinations of them – chords – instead of hunting for individual keys. A single finger produces a letter; two or three together produce others; modifiers give digits, symbols and control keys. The whole alphabet, numbers and punctuation fit under one hand.

The Vikid Arch Linux Wiki!

Sun, 11 Dec 2016 21:49:05 +0400

The Vikid Arch Linux Wiki!

Here is the truth about Arch Linux: it is not hard – it is manual. Every other distro hides decisions behind an installer; Arch asks you to make them, documents every step, and then gets out of the way. That is either exactly what you want or exactly what you don’t.

What it is, in plain words

Arch Linux is an independently developed, rolling-release GNU/Linux distribution for x86-64 (with official ports for other architectures under the Arch Linux name). Its personality:

Ubuntu CommonTasks

Sat, 10 Dec 2016 06:21:07 +0400

Ubuntu CommonTasks

Here is a truth about Ubuntu: most “how do I…?” questions have one canonical answer, and once you know the pattern you stop searching. This page is a pocket card of those answers – the tasks people actually do on a fresh Ubuntu box.

What it is, in plain words

Ubuntu is Debian’s friendlier cousin: same .deb packages and apt, a fixed release cadence (April and October), with LTS releases supported for five years (ten with Ubuntu Pro). The current LTS at the time of writing is 24.04 “Noble Numbat”; non-LTS releases get nine months. Underneath, since 15.04, the init system is systemd, so service management is systemctl and logs are journalctl – the old service apache2 status style still works as a thin wrapper, but the native commands are the ones to learn.

Linux Introspection

Fri, 09 Dec 2016 21:44:03 +0400

Linux Introspection

Here’s a truth that makes Linux wonderful to learn on: the system will tell you almost everything about itself if you just ask. No hidden registry, no magic – mostly plain text files and a handful of honest little commands.

What it is, in plain words

Introspection means a system examining itself. On Linux that means finding out: what distribution and kernel am I running, what hardware is here, what’s running, what’s using the disk, the memory, the network – and why it booted the way it did.

Linux Memory and Process

Sun, 04 Dec 2016 03:19:10 +0400

Linux Memory and Process

The truth behind every running program on Linux: each process believes it has the whole machine’s memory to itself. It doesn’t. The kernel and the CPU are running a very convincing illusion called virtual memory, and once you see how it’s staged, processes stop being mysterious.

Simple Linux Configuration

Wed, 30 Nov 2016 04:21:15 +0400

Simple Linux Configuration

Here is the truth about configuring Linux: almost everything is a text file, and the system will tell you which one if you ask. Once that sinks in, “configuration” stops being a mystery and becomes a short list of files you actually touch.

Linux Tools

Tue, 29 Nov 2016 09:36:50 +0400

Linux Tools

Here is a truth every Linux user eventually learns: the system is covered in small, sharp tools, and fluency means knowing which one to reach for. You don’t memorise every flag – you memorise the names, so that when a problem appears you think “that’s a job for strace” instead of staring at it.

What it is, in plain words

“Linux tools” here means the everyday command-line utilities that inspect, control and debug a running Unix system. Some come from GNU coreutils (ls, cp, sort), some from util-linux and procps-ng (ps, free, mount), some from binutils (objdump, nm, readelf), and some are specialised projects of their own (strace, tcpdump, ncdu). Together they are how you see what the kernel and your programs are actually doing.