*Memory Matrix

To add a new virtual disk and move the existing Linux partition to the new disk use the following process. The process assumes standard partitions without the use of Logical Volume Manager (LVM).

1. Backup the existing VM. One good way to do that is to clone the Virtual Machine and use the procedure on the new Virtual Machine.

2. Create the partition and format it.

$ mount /dev/sbd /mnt

$ shopt -s dotglob

$ rsync -aulvXpogtr /var/* /mnt

$ nano /etc/fstab

Add this line, replacing sdb and ext4 as necessary:

/dev/sdb /var ext4 defaults,noatime,nofail 0 2

Then

$ mv /var/ /var.old

Reboot and enjoy the new drive.

Minecraft Java edition lost compatibility with Java 17 between 1.20.4 and 1.20.6. Version 1.20.4 works with Java 17, and 1.20.6 no longer works with Java 17.  Several guides appear online for installing downloaded packages of the 64-bit runtime from Oracle or other sources.  Since Debian offers 32-bit server operating systems in the present day, the package manager versions are the easiest option if one uses the 32-bit version of Debian.  One of the reasons to use the 32-bit version of Debian is for use with older versions of Minecraft such as 1.10 and 1.12.  The older versions’ ecosystem contain an incredible number of mods.  The older versions require 32-bit java runtimes and the easiest way to handle that is to use a 32-bit operating system and then one can have newer versions of Java alongside older versions of Java and then one can run any version of Minecraft and Minecraft Forge that they desire.

Edit /etc/apt/sources.list to contain the following lines:

deb http://deb.debian.org/debian testing main
deb-src http://deb.debian.org/debian testing main

Then, run the following commands.

apt-get update
apt-get install openjdk-21-jre

java –version

https://wiki.debian.org/DebianTesting contains a good reference guide for using Debian Testing, including details on upgrading to the next distribution.  The approximate Java lifecycle can be found at https://www.oracle.com/java/technologies/java-se-support-roadmap.html.

1. R² is the coefficient of determination, which is the square of the Pearson correlation coefficient, r, the formula for which is ρ=β₁(σx/σy), where β₁ is the parameter estimate. ASCI and Unicode text does not have a circumflex, ^, on top of the β. For this documentation the objective is multiplatform long-term readability so an equation editor with specialized support for circumflexes is out of the question.

2. There is also the existence of the rejection region method. We reject the null hypothesis if the test statistic’s absolute value is greater than the critical value, which we can express with the formula Reject if |t| > t_α/2,n-1

Open the Thunderbird program folder (e.g. C:\Program Files (x86)\Thunderbird)
create a new folder named distribution
Create a file named policies.json with the following content:

{
    "policies": {
    "DisableAppUpdate": true
    }
}

Thanks to sifferedd.

Use printenv to see what environment variables are set.

#!/usr/bin/env bash
printenv
    set -x

Edit $HOME/.nanorc to contain the following:

include /usr/share/nano/java.nanorc
include /usr/share/nano/man.nanorc
include /usr/share/nano/nanorc.nanorc
include /usr/share/nano/python.nanorc
include /usr/share/nano/sh.nanorc
include /usr/share/nano/html.nanorc
include /usr/share/nano/perl.nanorc
include /usr/share/nano/php.nanorc

CentOS 7 uses a much older version of nano than the one that presently ships on most distributions. The php.nanorc on newer The following should appear in /usr/share/nano/php.nanorc on CentOS7 to allow syntax highlighting for php:

## Syntax highlighting for PHP

syntax "php" "\.(php[23457s~]?|phtml|ctp)$"

# PHP markings.
color brightgreen "()"

# Function names.
color white "\

The .bashrc file I use on CentOS6

# .bashrc

# User specific aliases and functions

alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'

# Source global definitions
if [ -f /etc/bashrc ]; then
        . /etc/bashrc
fi

# system variables
export VISUAL=nano  # sets nano as the crontab editor
export GZIP=-9      # maximum compression
export XZ_OPT=-9    # maximum compressions

# ls modifications
alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'

# calculator
calc() { echo "$*" | bc -l; }

# Generate a UUID
uuid() { UUID=$(cat /proc/sys/kernel/random/uuid) && echo $UUID; }

# CHANGE SHELL/WINDOW TITLE
# Works on Opensuse 15.3
# PS1=$PS1"\[\e]0;test1\a\]"
shellrename() { read -p "Enter new shell name: " name && PS1=$PS1"\[\e]0;${name}\a\]"; }

# For older versions of gnome-terminal
# shellrename() { read -p "Enter new shell name: " name && PROMPT_COMMAND='echo -ne "\033]0;${name}\007"'; }

# Zen Burn
# Another old way that works great in gnome-terminal while causing problems
# in some configurations involving SSH:
echo -ne '\e]12;#BFBFBF\a'
echo -ne '\e]10;#DCDCCC\a'
echo -ne '\e]11;#3F3F3F\a'
echo -ne '\e]4;0;#3F3F3F\a'
echo -ne '\e]4;1;#705050\a'
echo -ne '\e]4;2;#60B48A\a'
echo -ne '\e]4;3;#DFAF8F\a'
echo -ne '\e]4;4;#506070\a'
echo -ne '\e]4;5;#DC8CC3\a'
echo -ne '\e]4;6;#8CD0D3\a'
echo -ne '\e]4;7;#DCDCCC\a'
echo -ne '\e]4;8;#709080\a'
echo -ne '\e]4;9;#DCA3A3\a'
echo -ne '\e]4;10;#C3BF9F\a'
echo -ne '\e]4;11;#F0DFAF\a'
echo -ne '\e]4;12;#94BFF3\a'
echo -ne '\e]4;13;#EC93D3\a'

The best alias for ls is

ls –halF

It is easy to remember, and produces easy to read output with human readable file sizes and / marks present by the directory names.

Document z240302wa, last modified 2 March, 2024

dnf install oracle-epel-release-el9
dnf install iftop

iptraf is already in the default repositories.

A really good version of the ll alias is:

ls –lahF, although on some versions ls –lahp looks better than F.

Some useful aliases that are not always preconfigured on every Linux version:

alias ll=’ls -alF’
alias la=’ls -A’
alias l=’ls –CF’

To eliminate the DRM warning in Firefox and Librewolf without enable DRM, add this to “userChrome.css”:

 notification[value="drmContentDisabled"]{ display:none !important; }

toolkit.legacyUserProfileCustomizations.stylesheets must be set to true in about config.

The following script scans PDFs via an auto-document feeder in Hp-Lip and then collates the pages to the correct order when there are reverse sides. No scans will be saved if no data is transmitted for the second set of scans. The second set of scans is the reverse of the pages.

#!/usr/bin/env bash

YMD=$(date +"%Y-%m-%d")
Y=$(date +"%Y")
WORKDIR=/home/username/Temp/
OUTPATH=/home/username/Scans/${Y}/
#  Create a folder, ~/Temp and create a folder, ~/Scans
mkdir -p "/home/username/Scans/${Y}"

hp-scan --adf --mode=color &&
PART=hpscan
LATESTSCAN=`ls -t ${PART}*pdf | sed "1q"`
echo "${LATESTSCAN} ready for ${FILEOUTPUT}"

#  Why you shouldn't parse the output of ls
#  http://mywiki.wooledge.org/ParsingLs 
#  This does not use the FILEOUTPUT variable itself because the cp command
#  seems to have trouble copying the file correctly, even with switches. 

# Thanks Elektropepi at https://github.com/qpdf/qpdf/issues/259
function pdfscanmerge() {
	if [ $# -ne 3 ]; then 
		echo "Usage: pdfscanmerge
"; return; fi let odd_pages=$(qpdf --show-npages $1) let even_page=$(qpdf --show-npages $2) argument= for (( odd_page=1; odd_page0 ]; then argument+="$2 $even_page " fi let even_page-- done qpdf --empty --pages $argument -- $3 } cp ${LATESTSCAN} "$WORKDIR$1-uncompressed-scanned-${YMD}.pdf" gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/prepress -sOutputFile="$OUTPATH${YMD}-$1.pdf" ${LATESTSCAN} sleep 1 rm -f ${LATESTSCAN} rm -f "$WORKDIR$1-uncompressed-scanned-${YMD}.pdf" killall evince read -p "Load the reverse sides and press any key:" n hp-scan --adf --mode=color && PART=hpscan LATESTSCAN=`ls -t ${PART}*pdf | sed "1q"` echo "${LATESTSCAN} ready for ${FILEOUTPUT}" cp ${LATESTSCAN} "$WORKDIR$1-uncompressed-scanned-reverse-${YMD}.pdf" gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/prepress -sOutputFile="$OUTPATH${YMD}-$1-reverse.pdf" ${LATESTSCAN} sleep 1 rm -f ${LATESTSCAN} rm -f "$WORKDIR$1-uncompressed-scanned-reverse-${YMD}.pdf" killall evince pdfscanmerge "$OUTPATH${YMD}-$1.pdf" "$OUTPATH${YMD}-$1-reverse.pdf" "$OUTPATH${YMD}-$1-collated.pdf" rm -f "$OUTPATH${YMD}-$1.pdf" rm -f "$OUTPATH${YMD}-$1-reverse.pdf"