Archive for the 'Computing Notes' Category

Data Science Time Warp Machine

Published on February 23, 2025 in Computing Notes.

Fedora 38 freezes up and crashes sometimes when using Gnome on bare metal.  This may be the result of Gnome reliability issues.  In a previous article I detailed creating a massive repo of Fedora 38, and I still have it.  I will not delete the 238GB repo because Fedora 40 is the last one with Python 2.7 in the repositories.  They elected to completely remove it in Fedora 41 and beyond.  I created some software in Python 2.7 that may never make it to Python 3 because I will be an old man by the time I could complete the conversion relative to my available time in the present day. I had migrated from bare metal to WSL with Fedora 36 a few years ago. I had created my own WSL instance using the Fedora 36 cloud init image, and then upgraded it over the years to Fedora 38 and then ceased updating it.  WSL crashes and cannot be relied upon to run tasks that require many hours of continuous processing.

WSL really was wonderful for development and running Linux applications with underlying Linux features.  I used it for development using Pycharm.  The problem is that I would often return after 12 hours and see a message that the terminal could be closed with a CTRL + D which indicated that the service had stopped for some reason.  I suspect these occurred when available RAM conflicted with the /dev/share features of Linux.  Troubleshooting it would take too long. I don’t trust the releases from the Windows store because forced updates in Windows can take features away or cause unexpected problems.  I upgraded my Windows 11 home desktop to Windows 11 Pro specifically so I could disable Windows automatic updates via group policies, service disablement, and registry modifications that fail to stop auto updates on Windows 11 Home.

To create a long use time capsule of sorts, I decided to switch to Alma Linux 8 from Fedora 38.  Alma Linux 9 follows the tradition of RHEL 9 and removes the easy support for Python 2.

I setup Alma Linux 8.10 Cerulean Leopard, installed from the KDE live DVD, and installed r Studio server to access via web browser.

edit /ect/dnf/dnf.conf and add keepcache=True

dnf install epel-release    
dnf config-manager -enable powertools    
dnf install R    
dnf install python2

The python2 install installs pip2.7 automatically. One calls pip2 via the pip2.7 command.

As regular user the following is required for a script I made because parsedatetime changed after version 2.5 and is no longer compatible with the previous versions.

pip2.7 install parsedatetime==2.5 --user

• Install rstudio-2024.12.0+467-1.rpm from direct download

• Install rstudio-server-rhel-2024.12.0-467.rpm from direct download

systemctl enable rstudio-server

Configure the firewall to allow 8787.

usermod -a -G rstudio-server <username> 
setenforce 0

The last instruction to turn off SELinux is temporary until I can ascertain the specific rules that will need modification to allow it work. With SELinux enforcing with the initial configuration, the server cannot be accessed via web browser remotely

Tags: , , , , .

Blog code and general code release note system

Published on February 22, 2025 in Computing Notes.

Today’s site updates including removing the RSS feed links. Kinsta provided source code.1  The code for functions.php to remove it is:

remove_action( 'wp_head', 'feed_links_extra', 3 );
remove_action( 'wp_head', 'feed_links', 2 );

Kinsta also provided another very useful function2 and that was one that removed the various update notifications in the dashboard.

function kinsta_hide_update_nag() {
remove_action( 'admin_notices', 'update_nag', 3 );
}

add_action('admin_menu','kinsta_hide_update_nag');

Another very useful function for WordPress is one where you may add additional mime types for upload to the library.  This is useful for uploading compressed archives in different formats. Chris Meller’s venerable blog provides the source.3

add_filter('upload_mimes', 'custom_upload_mimes');
function custom_upload_mimes ( $existing_mimes=array() ) {

	// add your ext => mime to the array
	$existing_mimes['xz'] = 'application/x-xz';
        $existing_mimes['zip'] = 'application/zip';
	$existing_mimes['xml'] = 'application/xml';

	// add as many as you like
	// and return the new full result
	return $existing_mimes;

}

Somewhere along the way I picked up the following items to use as release notes within the scripts that I create.

E.g. 11/05/2024: [*] Changed URL to 1.1.1.1 from 8.8.8.8

[+] = Added
[*] = Changed  
[^] = Moved  
[=] = No Changes  
[x] = Deleted  
[!] = Bugs  
[_] = To Do  
[>] = Migrated  
[<] = Migrated

1. Kinsta®. “WordPress Disable RSS Feed,” August 30, 2016. https://kinsta.com/knowledgebase/wordpress-disable-rss-feed/.

2. Kinsta®. “How To Disable WordPress Update Notifications (Plugin or Code),” July 4, 2022. https://kinsta.com/knowledgebase/disable-wordpress-update-notification/.

3. Meller, Chris. “Modifying Allowed Upload Types in WordPress | Chris Meller,” July 26, 2007. https://blog.chrismeller.com/modifying-allowed-upload-types-in-wordpress.

Tags: , , .

Monitoring network connections on Linux

Published on November 25, 2024 in Computing Notes.

Here is a great TCP/UDP Port finder tool.   This was useful for finding out which port “cbt” was in my Iftop listing.  It was 7777, which was in use for the Unreal Engine on an Ark: Survival Evolved game server. Iftop is the best real time network monitoring tool for Linux that has graced my system to date — or so it seems until one finds Iptraf. Iptraf is another excellent tool for monitoring network traffic in real time.  The Iptraf manual is here.  Netstat wasn’t suitable for this purpose due to the use of UDP as the main protocol.  Netstat is certainly useful, but no switches that I could locate would enable the program to show the UDP traffic in real time and the associated addresses of those connected to the server.  Iptraf shows the UDP traffic in a rapidly updating scroll box.  Iftop shows the traffic in an easy to read display that includes the address and hostname of the connected system.

This list doesn’t relate to more in depth management tools. This list is for easy console monitoring of a server running such games as ARK Survival Evolved.

Tags: , .

Install cron on Fedora 38

Published on October 21, 2024 in Computing Notes. 
dnf install cronie
systemctl enable crond.service
systemctl start crond.service
Tags: , , .

Building an anti-bitrot bunker

Published on October 20, 2024 in Computing Notes.

When I first obtained a CompTIA A+ certification some time ago, the concept of bit rot related to what happens to software reliability as the number of updates to the system increases. Over time, software that worked in years past ceases to work as new system updates block system calls or change permissions and files that the software originally relied upon. This slow decaying of reliability was called bit rot. There are some other definitions floating around on the internet, but that is the one most relevant for me.

To prevent this and reduce the amount of time spent in sorting out the bit rot introduced to my investments by Microsoft’s proclivities, I have standardized on two operating systems for major time investments in computing that occupy my life.  Windows still has a place since I sometimes use Windows only games to play with my child.  Other than that necessity, I have built the things I rely on for use with Linux.  The two versions that I have standardized on are Debian and Fedora. Specifically Debian 12 and Fedora 38.  These are not what is used for the website, but they are the major components of my anti-bitrot infrastructure.  I am aware this may not be good security practice, but this isn’t to get me a job, this is to serve an aging man and his family reliably over time.

There are a few reasons that I selected Fedora 38 and Debian 12. Fedora 38 still has Python 2.7 in the repositories.  It was within 2 versions for upgrading from Fedora 36. Fedora 36 was what I was running in my Windows Subsystem for Linux instance, and I upgraded it to Fedora 38.   When deciding to move back to bare metal for my Linux software development and automation needs, I decided to standardize on that one.  Debian has a 32 bit version. I have both the 32-bit and 64-bit deployed in my network.  Debian 32 bit allows on to easily 32-bit builds of Java on a Linux server.  One can add the testing repository and have the latest Java in 32 bit form.  32-bit Java is necessary to run older Minecraft versions.  My family has a large set of mod-collections and old Java Minecraft instances and maps going back about 8 years. I can then run the latest JVM and the latest Minecraft on the same server because the 32bit JVM is available.  It is very annoying to try and  manage 32bit and 64bit Java virtual machines on the same host, so having it all 32-bit solves a huge problem.  One can add the Debian 11 repository and install Python2.7 if one wants to use old Python versions.  I need this old Python version for a project that I worked on over the course of the last 8 years.

The general anti-bit rot measure for Debian is to always use apt-get to install packages as this will leave the .deb file in the cache.  Then copy those .deb files on a regular basis to another location for use as a repository for other Debian installations.  This can be configured to work via a cron job.  Debian is really the only long-term viable game in town if one wants a 32-bit anti-bitrot bunker that will last into the future, over say, a ten year time horizon. Save the .deb files on a private web-server inside the network and periodically update that repository with the files copied via the sweeps from the cache directory.

For Fedora, this should work with any version.  Fedora 38 is the one I use.  Edit the /etc/dnf/dnf.conf file to say keep_cache=True, and this will save the dowloaded RPMS.  One can then build their repository using only what they need if so desired.  The other genuine long term standardization option is to mirror the entire repositories to the private webserver within one’s network.  To do this, install yumdownloader.   Then, move all of the .repo files from /etc/yum.repos.d except for one to a temporary location.  Then, go into a directory with a lot of space.  For Fedora 38, the complete mirror was 229GB.  Then use yumdownloader * and it will download all files from that repository.  Then, use yumdownloader –source * and it will download all source packages for the packages that it just downloaded.  Then, go back to /etc/yum.repos.d and switch that .repo file out with one that was moved previously, and repeat the process until all repositories have been completely downloaded.  Then, copy all downloaded RPMS to one large directory on the webserver and use createrepo to create the meta data.  Then on the client machines, create a .repo pointing to your own webserver, and move the existing .repo files in /etc/yum.repos.d to an archival location.   Then all of your installations will occur from your own webserver and all machines will have the same versions of packages.

In my case, I then install the data science specifics that I need for the automated software that I created.  The process varies slightly depending on whether the system is Fedora or Debian.

For Debian:

Add bullseye to sources.list
Install python2 via bullseye repositories
Install pip via the downloaded file from https://linuxhint.com/install-pip-on-debian-11/ that is to say,
1. wget https://bootstrap.pypa.io/pip/2.7/get-pip.py
2. python2 ./get-pip.py
Apt-get install libcurl4-openssl-dev

R:
Install.packages(‘curl’)
Install.packages(‘fpp2’)
Install.packages(‘magrittr’)
Install.packages(‘urca’)
Install.packages(‘vars’)
Install.packages(‘psych’)
Apt-get install r-cran-rjava
Install.packages(‘rJava’)
Install.packages(‘xlsx’)
Install.packages(‘Hmisc’)
Install.packages(‘prophet’)
Install.packages(‘dplyr’)
pip2 install parsedatetime==2.5
apt-get install awscli
pip2 install boto3
apt-get install r-cran-car

Troubleshooting steps if .xlsx and others are not built:
Are all R packages installed successfully with a 0 exit status?

On Fedora, the repositories do not contain R components in the same way the Debian repositories do.  Here is the process for Fedora 38.

Used the script https://bootstrap.pypa.io/pip/2.7/get-pip.py
pip2 install parsedatetime==2.5 –user
dnf install libcurl
dnf install libcurl-devel
dnf install R
dnf install awscli
pip2 install boto3 –user
dnf install cmake

Within R:
install.packages(‘car’)
install.packages(‘curl’)
install.packages(‘fpp2′)
install.packages(‘magrittr’)
install.packages(‘urca’)
install.packages(‘vars’)
install.packages(‘psych’)
install.packages(‘rJava’)
install.packages(‘xlsx’)
install.packages(‘Hmisc’)
install.packages(‘prophet’)
install.packages(‘dplyr’)

Tags: , , , .

Shrink Firefox Interface

Published on June 24, 2024 in Computing Notes.

Use about:config –> browser.uidensity .

browser.uidensity is set to 0 by default.  Changer the  value to 1 and it takes immediate effect.

Tags: , .

VirtualBox Disk Conversion

Published on June 10, 2024 in Computing Notes.

To convert a dynamic VirtualBox disk to a Fixed disk, run the following command:

vboxmanage clonemedium disk /path/disk.vdi /path/newdisk.vdi -variant Fixed

using –variant Standard would create a dynamic disk.  Then open the virtual machine and remove the existing disk and attach the new disk.  Then use the media manager to delete the unused media.

Use the following command to list registered virtual disks:

vboxmanage list hdds
Tags: , , .

Browser Extensions

Published on June 10, 2024 in Computing Notes.

Chromium:

Joplin Web Clipper, Zotero Connector, floccus bookmarks sync, uBlock Origin, Quick Javascript Switcher, SingleFile, uMatrix

Firefox:

SingleFile, Copy PlainText, floccus bookmarks sync, Joplin Web Clipper, Passman, Search by Image, Tree Style Tab, uMatrix, Undo Close Tab, Web Archives

Tags: , , , .

Debian 12 PATH and X11

Published on May 18, 2024 in Computing Notes.

A few quirks with Debain 12 include that path not being set in similar fashion to Fedora, Ubuntu, and other distributions.  One must regularly set

export PATH=$PATH:/usr/sbin

In Gnome, applications will open on the server instead of the client when using X11 forwarding.  This will occur even though xcalc opens on the client normally.  The way to avoid this is to add the following to .bashrc

unset XDG_RUNTIME_DIR 
unset GDK_BACKEND

The general rule is compress, then encrypt.1, 2

1. https://stackoverflow.com/questions/4676095/when-compressing-and-encrypting-should-i-compress-first-or-encrypt-first

2. https://crypto.stackexchange.com/questions/33737/is-it-better-to-encrypt-before-compression-or-vice-versa

Tags: , , , , .

Move /var to new disk

Published on May 18, 2024 in Computing Notes.

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.

Tags: , .

Install Java 21 in Debian 12

Published on May 4, 2024 in Computing Notes.

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.

Tags: , , , .

Disable updates in Thunderbird

Published on April 2, 2024 in Computing Notes.

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.

Tags: , .

Print environmental variables in Bash

Published on April 2, 2024 in Computing Notes.

Use printenv to see what environment variables are set.

#!/usr/bin/env bash
printenv
    set -x
Tags: , .

.nanorc in CentOS

Published on April 2, 2024 in Computing Notes.

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 "\
Tags: , , .

The .bashrc file I use on CentOS6

Published on April 2, 2024 in Computing Notes.

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'
Tags: , , .

The best Alias for ls

Published on March 2, 2024 in Computing Notes.

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..

Tags: , .

Install iftop on Oracle Linux 9

Published on February 23, 2024 in Computing Notes.

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

iptraf is already in the default repositories.

Tags: , , , , .

A good version of ll

Published on February 20, 2024 in Computing Notes.

A really good version of the ll alias is:

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

Tags: , .

LS alias and Mozilla DRM bar

Published on February 11, 2024 in Computing Notes.

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.

Tags: , , .

Double Sided Scan and PDF

Published on February 1, 2024 in Computing Notes.

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"
Tags: , , , , .

Automated Database Restart

Published on January 21, 2024 in Computing Notes.

Here is a script that checks to ensure the database is running and restarts the service if it is not running.  This was used on a very low memory server to ensure a database remained operational, despite it sometimes crashing due to out of memory errors.

#!/bin/bash

timestamp="$(date)"
systemctl stop httpd && echo "${timestamp}" Stopping Apache... >> /home/centos/administration/apache.log
systemctl is-active mariadb && echo "${timestamp}" MariaDB is active so not starting >> /home/centos/administration/mariadb_active.log || echo "${timestamp}" MariaDB is not Active >> /home/centos/administration/mariadb_inactive.log
systemctl is-active mariadb && echo "${timestamp}" No need to restart MariaDB || systemctl start mariadb
systemctl start httpd && echo "${timestamp}" restarting apache...>> /home/centos/administration/apache.log
Tags: , , , , .

AppImage Integration

Published on January 21, 2024 in Computing Notes.

To install AppImages and integrate them with the desktop environment like a conventional package,  use the AppImage Launcher. LibreWolf’s documentation contains a how-to document on using AppImage Launcher.

Tags: , , .

Thunderbird Row Highlighting

Published on January 21, 2024 in Computing Notes.

Revisions: 21 January 2024, first publication

The Thunderbird developers are moving to a new user interface code base for Thunderbird 115 and Thunderbird 102 is the last version that will work with the historical userChrome.css customizations. The userbase for Mozilla products has continually shrunk over the past few years and the chances of equivalent customization abilities being discovered and written about strike me as pretty low.  Because of the change, I have mirrored Thunderbird 102.14 for Windows and Linux in 64-bit and 32-bit versions in the event that the old versions disappear from the Mozilla site. The Source is available on the Mozilla mirror as of August 11, 2023.  The releases are located here.

The userChrome.css below allows the following persistent tag colors.  It also contains text customization for the interface.  And it contains alternate row highlighting, where one row is light grey and the other white.  The alternate row highlighting conflicts with the background colors for tags.  One must choose which feature to have. The userChrome.css goes in the profile directory in a subfolder called chrome.

Screenshot 2024-01-21 151250
The code for highlighting the tag backgrounds was found on a French website located here. E.g. C:\Users\username\AppData\Roaming\Thunderbird\Profiles\1a2b3cde.default-release\chrome

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
/* set default namespace to XUL */
/* thanks to Jean-Claude, */
/* https://forums.mozfr.org/viewtopic.php?t=143173 */
/*Important tag IMPORTANT*/ 
treechildren::-moz-tree-row(T_24label1)
{
      border-bottom: 1px solid #FFFFFF !important;
      background-color:  #FF0033   !important;
}
treechildren::-moz-tree-cell-text(T_24label1)
{
      color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label1, selected)
{
      background-color: #b71c1c !important;
}
treechildren::-moz-tree-cell-text(T_24label1, selected)
{
  color: #00FF00  !important;
}

/*Travail tag   WORK*/
treechildren::-moz-tree-row(T_24label2)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #FF9900   !important;
}
treechildren::-moz-tree-cell-text(T_24label2)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label2, selected)
{
  background-color: #FF9900 !important;
}
treechildren::-moz-tree-cell-text(T_24label2, selected)
{
  color: #00FF00  !important;
}

/*Personnel tag PERSONAL*/ 
treechildren::-moz-tree-row(T_24label3)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #009900   !important;
}
treechildren::-moz-tree-cell-text(T_24label3)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label3, selected)
{
  background-color: #009900 !important;
}
treechildren::-moz-tree-cell-text(T_24label3, selected)
{
  color: #00FF00  !important;
}

/*A faire tag*/
treechildren::-moz-tree-row(T_24label4)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #3333FF   !important;
}
treechildren::-moz-tree-cell-text(T_24label4)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label4, selected)
{
  background-color: #3333FF !important;
}
treechildren::-moz-tree-cell-text(T_24label4, selected)
{
  color: #00FF00  !important;
}

/*Peut attendre tag*/
treechildren::-moz-tree-row(T_24label5)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #993399  !important;
}
treechildren::-moz-tree-cell-text(T_24label5)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(T_24label5, selected)
{
  background-color: #993399 !important;
}
treechildren::-moz-tree-cell-text(T_24label5, selected)
{
  color: #00FF00  !important;
}

/*test tag*/
treechildren::-moz-tree-row(Ttest)
{
  border-bottom: 1px solid #FFFFFF !important;
  background-color:  #FFCC33  !important;
}
treechildren::-moz-tree-cell-text(Ttest)
{
  color: #FFFFFF !important;
}
treechildren::-moz-tree-row(Ttest, selected)
{
  background-color: #FFCC33 !important;
}
treechildren::-moz-tree-cell-text(Ttest, selected)
{
  color: #00FF00  !important;
}

/* 9 August 2023 Additions */
/* Set Font Size In Folder Pane */

#folderTree >treechildren::-moz-tree-cell-text {
  /*font-family: Lucida Sans !important;*/
  font-size: 9pt !important; }

/* Set Font Size In Thread Pane */

#threadTree >treechildren::-moz-tree-cell-text {
  /*font-family: Lucida Sans !important;*/
  font-size: 9pt !important; }

#threadTree treechildren::-moz-tree-row    {
/*  border-bottom: 1px dotted grey !important;  */
  height: 24px !important; }

/* folder list spacing */

#folderTree treechildren::-moz-tree-row    {
  height: 24px !important; }

/* The silver background color on alternating rows */
#threadTree treechildren::-moz-tree-row(odd) {
  -moz-appearance: none !important;
  background-image: none !important;
  /* the !important property overrides previous styling rules */
  /* this line enables alternate color row highlighting, but
  tag backgrounds on this row cannot be highlighted.  Only one 
  background highlighting can be applied Disabled 9 August 2023
  to enable tag background highlights*/
  /* background-color:#F3F6FA !important; */

}

#threadTree treechildren::-moz-tree-row(selected) {
  background-color: -moz-Dialog !important;
}
#threadTree treechildren::-moz-tree-row(selected, focus) {
  background-color: Highlight !important;
}

#folderTree treechildren::-moz-tree-row(selected) {
  -moz-appearance: none !important;
  background-image: none !important;
  background-color: Highlight !important;
}
#folderTree treechildren::-moz-tree-row(selected, focus) {
  -moz-appearance: none !important;
  background-image: none !important;
  background-color: Highlight !important;
}
Tags: , .

Functions in Bash

Published on January 21, 2024 in Computing Notes.

This is the code for a function in Bash script.

 #!/bin/bash
 # Define a function
 greet() {
 echo "Hello, $1"
 }
 # Call the function with "World" as the argument
 greet "World"
Tags: , .

Looping through filenames in Bash

Published on January 21, 2024 in Computing Notes.

To loop through the subdirectories in a folder, when those subdirectories may contain spaces in the file names, use the following procedure.

OLD_IFS=$IFS && IFS=$'\n'
 for directory in $HOME/somefolder/*/; do
 echo “some code here”
 done
 IFS=$OLD_IFS

 

Tags: , .

Bash and *nix Note no. 2

Published on January 10, 2024 in Computing Notes.

 

This document contains some notes on .bashrc for use with Linux systems.

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

if [ -f ~/.bash_aliases ]; then
. ~/.bash_aliases
fi

The preceding two blocks come standard on Ubuntu as of version 2022.04. One tweak for WSL2 on Windows might be the addition of this line.

sudo bash “/etc/rc.local”

and in the rc.local follow, add the following.

#!/bin/bash
rm -f /etc/resolv.conf
echo “nameserver 1.1.1.1″ >> /etc/resolv.conf
echo “nameserver 8.8.8.8″ >> /etc/resolv.conf

This is because WSL2 may place non-routable IP addresses using 172… in resolv.conf. As of this writing, following steps recommended to disable the generation of the file fails to resolve the issue where the file is newly generated with every new terminal launched in Windows terminal. Having this run with each new Bash login ensures success with network communications.  The location /etc/rc.local may seem like an odd location for this.

The crontab to ensure to check each minute to ensure a virtual machine is running in VirtualBox is as follows.

*/1 * * * * VBoxManage startvm “VMNAME” –type headless
*/1 * * * * VBoxManage startvm “VMNAME2″ –type headless

If the virtual machine is already running, then it will not start a new copy of it. This is better than attempting to run the script via a system wide script after a reboot.  Running it this way allows a simple crontab for the user for whom the machine needs to run under. To run a script every five minutes, add the crontab as follows:

*/5 * * * * /home/USERNAME/nextcloudcron

In this example, the nextcloudcron script will run every five minutes.  This particular script is one for use contacting my Nextcloud instance for webcron.  It does not contain a .sh on the filename, because some implementations may disallow crontab scripts with file extensions.

The following checks inside a subdirectory and pulls in the files therein as bash sources. This is useful for breaking aliases, variables, and other items into different files.

if [ -d ~/.bashrc.d ]; then
for rc in ~/.bashrc.d/*; do
if [ -f "$rc" ]; then
. “$rc”
fi
done
fi

The following uses nano as the crontab editor.

export VISUAL=nano

On Oracle Linux 9 on AWS, it is necessary to install Cronie to enable cron jobs.  To ensure this starts after reboots, add the following to /etc/rc.local.

bash /sbin/crond

To create a date line for a log file, use the following:

echo $(date) >> /home/USER/FILENAME

The Shebang for the top of bash files is

#!/usr/bin/env bash

To auto-update via DNF and leave a log of what was accomplished, use the following script.  The script will write a list of the updates to the systemupdates.log file, and then update the system with details of that process written to the dnfupdates.log file.

#!/usr/bin/env bash
echo $(date) >> /home/USER/systemupdates.log
sudo dnf check-update >> /home/USER/systemupdates.log
echo $(date) >> /home/USER/dnfupdates.log
sudo dnf update -y >> /home/USER/dnfupdates.log 2>&1

Tags: , , , , .

Bash and *nix Note no. 1

Published on July 7, 2023 in Computing Notes.

7 July 2023:
Ubuntu 22.04′s update notifier seems to not include the option to configure any settings, at least after certain conditions exist on a particular system.  To stop the notifier from appearing.  To stop the notifier from appearing use

sudo apt-get remove update-notifier

7 July 2023:
There are non-snap builds of ungoogled-chromium for Ubuntu

6 July 2023 and prior:

To disable automatic updates on Ubuntu:

sudo dpkg-reconfigure unattended-upgrades
sudo apt remove packagekit


In .bashrc create the following alias:




alias nano="nano -c --guidestripe 80"




This will open always Nano with line and column numbering along with a long line marker at the specified column. The long line marker feature works for Nano version higher than 4, which doesn’t include the version in the CentOS 7 repositories.


In .bashrc add the following line:




export DISPLAY=\
"`grep nameserver /etc/resolv.conf | sed 's/nameserver //'`:0"




This adds the IP address of the instance to the display variable for use with Windows Subsystem for Linux and VcXsrv.


In .nanorc add the following items. The first two lines are commented because the command line switch used in the alias for the line numbers creates no artifacts when using copy-paste.




#set linenumbers
#set constantshow

# https://www.nano-editor.org/dist/latest/nanorc.5.html
set guidestripe 80

include /usr/share/nano/autoconf.nanorc
include /usr/share/nano/patch.nanorc
include /usr/share/nano/nanorc.nanorc
include /usr/share/nano/groff.nanorc
include /usr/share/nano/awk.nanorc
include /usr/share/nano/man.nanorc
include /usr/share/nano/java.nanorc
include /usr/share/nano/sh.nanorc
include /usr/share/nano/po.nanorc
include /usr/share/nano/texinfo.nanorc
include /usr/share/nano/python.nanorc
include /usr/share/nano/perl.nanorc
include /usr/share/nano/pov.nanorc
include /usr/share/nano/ocaml.nanorc
include /usr/share/nano/tcl.nanorc
include /usr/share/nano/debian.nanorc
include /usr/share/nano/lua.nanorc
include /usr/share/nano/xml.nanorc
include /usr/share/nano/gentoo.nanorc
include /usr/share/nano/objc.nanorc
include /usr/share/nano/tex.nanorc
include /usr/share/nano/guile.nanorc
include /usr/share/nano/php.nanorc
include /usr/share/nano/c.nanorc
include /usr/share/nano/nftables.nanorc
include /usr/share/nano/spec.nanorc
include /usr/share/nano/elisp.nanorc
include /usr/share/nano/ruby.nanorc
include /usr/share/nano/go.nanorc
include /usr/share/nano/nanohelp.nanorc
include /usr/share/nano/default.nanorc
include /usr/share/nano/json.nanorc
include /usr/share/nano/css.nanorc
include /usr/share/nano/mgp.nanorc
include /usr/share/nano/asm.nanorc
include /usr/share/nano/mutt.nanorc
include /usr/share/nano/javascript.nanorc
include /usr/share/nano/postgresql.nanorc
include /usr/share/nano/rust.nanorc
include /usr/share/nano/fortran.nanorc
include /usr/share/nano/cmake.nanorc
include /usr/share/nano/makefile.nanorc
include /usr/share/nano/html.nanorc
include /usr/share/nano/changelog.nanorc




Using Tar and Gzip:


tar -zcvf output_file_name[.tar.gz or .tgz] directory_to_compress


tar -Jcvf output_file_name[.tar.xz] directory_to_compress

reads compression level for XZ from environmental variable, but note that xz utils is not installed by default on ubuntu 10.04


tar -xvf works to extract .tar.gz file created like in the above


The Tar and Gzip commands use compression settings specified in .bashrc




export GZIP=-9

export XZ_OPT=-9




Add the following to .bashrc for a console calculator:




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




For the ll alias, use the following in .bashrc




alias ll='ls -alF'




To change the terminal name use the following in .bashrc.  The command differs depending upon which version of Gnome one uses.




# For older versions of gnome-terminal
#shellrename() { read -p "Enter new shell name: " name && PROMPT_COMMAND='echo -ne "\033]0;${name}\007"'; }
# Works on OpenSUSE 15.3
#PS1=$PS1"\[\e]0;test1\a\]"
shellrename() { read -p "Enter new shell name: " name && PS1=$PS1"\[\e]0;${name}\a\]"; }




To obtain a uuid, add the following to .bashrc:




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




Zen Burn color scheme for the terminal, but sometimes causes problems with work via SSH.




# 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'




Circa 2015: Adding Windows to CentOS 7 and Grub 2 after installing CentOS and no automatic configuration of Windows boot options. The file to manually edit is /etc/grub.d/40_custom.




menuentry "Windows 10 Professional" { set root=(hd0,1) chainloader +1 }




After editing, update Grub and reboot using the following command.




grub2-mkconfig –output=/boot/grub2/grub.cfg




The following shows one of the custom file contents circa 2018 or 2019 after some changes to installers and autodetection.




#!/bin/sh


exec tail -n +3 $0


# This file provides an easy way to add custom menu entries. Simply type the menu entries you want to add after this comment.


# Be careful not to change the 'exec tail' line above.


menuentry "Windows (system) (on /dev/sda1)" --class windows --class os { insmod part_msdos insmod ntfs insmod ntldr set root='(hd0,msdos1)' ntldr ($root)/bootmgr}



		


		

			
						

				Tags: , , , .			

			
					

	



	

		

			

				Minecraft Tweaks
			


			
						

				Published on March 16, 2023 in Computing Notes.			
 
			
					


		

						
To launch


java -Xms2048M -Xmx2048M --add-modules=jdk.incubator.vector -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -Dusing.aikars.flags=https://mcflags.emc.gs -Daikars.new.flags=true -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -jar server-1.21.1.jar nogui

		


		

			
						

				Tags: , , .			

			
					

	



	

		

			

				Labeling variables in R
			


			
						

				Published on February 2, 2020 in Computing Notes.			
 
			
					


		

						
This great procedure makes it easy to remember what variables are related to in R. One of the troubles with exploratory data analysis is that when one has a lot of variables it can be confusing what the variable was created for originally.  Certainly code comments can help but that makes the files larger and unwieldy in some cases.  One solution for that is to add comment fields to the objects created so that we can query the object and see a description.  So, for example, we could create a time series called sales_ts, and then create a window of that, called sales_ts_window_a, and another called sales_ts_window_b, and so on for several unique spans of time.  As we move through the project we could have created numerous other variables and subsets of those variables.   We can see the details of those by using head() or tail(), but that may not be an extremely useful and clear measure.


To that end, these code segments allow applying a descriptive comment to an item and then querying that comment later via a describe command.


example_object <- "I appreciate r-cran."
# This adds a describe attribute/field to objects that can be queried.
# Could also change to some other attribute/Field other than help.
describe <- function(obj) attr(obj, "help")
# to use it, take the object and modify the "help" attribute/field.  
attr(example_object, "help") <- "This is an example comment field."
describe(example_object)


The above example refers to an example object, that could easily be sales_ts_window_a mentioned above.  So we would use the attribute command to apply our description to sales_ts_window_a.


attr(sales_ts_window_a, "help") <- "Sales for the three quarters Jan was manager"
attr(sales_ts_window_b, "help") <- "Sales for the five quarters Bob was manager"


After hours or days have passed and there are many more variables under investigation, a simple query reveals the comment.


describe(sales_ts_window_a)
[1] "Sales for the three quarters Jan was manager"


This might seem burdensome, but RStudio makes it very easy to add this via code snippets. We can create two code snippets. The first is the one that goes at the top of the file which defines the describe function that we use to read the field we apply to the comment to. Open RStudio Settings > Code > Code Snippets and add the following code. RStudio requires tabs to indent these.


snippet lblMaker
        #
        # Code and Example for Providing Descriptive Comments about Objects
        # 
        example_object <- "I appreciate r-cran."
        # This adds a describe attribute/field to objects that can be queried.
        # Could also change to some other attribute/Field other than help.
        describe <- function(obj) attr(obj, "help")
        # to use it, take the object and modify the "help" attribute/field.  
        attr(example_object, "help") <- "This is an example comment field."
        describe(example_object)

snippet lblThis
        attr(ObjectName, "help") <- "Replace this text with comment"


Now one can use the code completion to add the label maker to the top of the script. Simply start typing lblMak and hit the tab key to complete the code snippet. When wanting to label an object for future examination, start typing lblTh and hit tab to complete it and replace the objectname with the variable name and replace the string on the right with the comment. These code snippets provide a valuable way to store descriptive information about variables as they are created and set aside with potential future use.


This functionality does overlap with the built in comment functionality with a bit of a twist. The description added via this method appears at the end of the print output when typing the variable name. The built in comment function does not print out. It is also less intuitive than describe() and receiving a description.


R contains a built in describe command, but it often is not useful. Summary is the one I use most often. For a good description, I import the psych package and use psych::describe(data). Because of that, the describe method in this article is very useful. The printout appears like below with the [1]…


lu71802xbt90_tmp_dac5c795


Adding attributes other than “help” could easily be accomplished. DescribeAuthor, DescribeLocation, and other functions could be added. When using a console to program, a conversational style makes it flow better.

		


		

			
						

				Tags: .			

			
					

	



	

		

			

				My Favorite Function
			


			
						

				Published on May 25, 2019 in Computing Notes.			
 
			
					


		

						
My favorite function of all time is varsoc in Stata.  That’s saying a lot because I have been working with computers for decades and have written software in several languages, used many different types of administrative software tool sets, and owned a lot of books with code in them.  Varsoc regresses one variable, y, upon another variable, x, and then regresses each lag of y on x to produce output that allows one to know the best fit lag for a regression model.   It allows someone analyzing time series data to immediately know that data from the several prior is a better predictor of today’s reality than more recent data.  I adore Stata for scientific analysis.  In order to use this for my big data project, I needed to automate it, and so I wrote an R vignette that would analyze 45 lags and produce the relevant test statistics. My vignette produces r2 values1, parameter estimates, and f-statistics for 45 lags of y regressed on x. The p-values are then written to a CSV file. The decision rule for a p-value is that we reject the null hypothesis if the p-value is less than or equal to α/2.2 The data comes from 5GB of CSV files that were created via Python.


Running the lags shows us the relationships between the historical prices of two securities. When we regress y on x in this case, we are regressing the price of security 2 on security 1. We then do this on a lag. The L1 of security 2 regressed on security 1’s L0. Then we regress L2 of security 2 on security 1’s L0. This occurs for 45 iterations. For example, we might find that the price of a gold ETF 44 days ago has the best relationship with the price of Apple stock today as compared to the price of that same gold ETF 12 days ago and even today. That’s an example only and not anything substantiated in the data. There will certainly be some spurious relationships. An ETF buying shares of Apple and then the same ETF’s fee going up the next month, for example. To mitigate this, the vignette uses the first difference of the logarithm so that the data is stationary. The CSVs are already produced so that unit roots are accounted for. This is a research project to identify what actually bodes well in other sectors. It runs on every listed security on the American exchanges. Every symbol is regressed on Apple. Every symbol is regressed on Microsoft, and so on. The data is stationary and unit roots are eliminated.


I initially began this project some time ago and at that time I stopped because it was going to take a solid month of continuous 12-core processing to accomplish the entire series. In retrospect, I should have let that proceed but there would have been a great tradeoff in that I couldn’t have played Roblox, The Isle, and Ark Survival Evolved with my daughter. Finally, I’ve got the research running on a new machine dedicated to that purpose. That machine uses an AMD Ryzen 5 3500 and NVMe SSD. The program is running on 6 cores in parallel. Previously, with the one month estimate, it was running concurrently on 12-cores of Westmere Xeon CPUs and storing the output in RAM instead of on an SSD. This will serve as an interesting test for the Ryzen since all six cores will be running at 100% for months on end. The operating system is OpenSuse Leap 15.2, the R version is 4.05, and the Python version is 2.7.18.


One of the reasons to write these articles is for my own memory. It gets older to remember as one gets older. These blog posts are essentially a public notebook to aid myself and others.




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| > tα/2,n-1

		


		

			
						

				Tags: , , , .			

			
					

	



	

		

			

				Synchronize time on CentOS 6
			


			
						

				Published on December 27, 2011 in Computing Notes.			
 
			
					


		

						
This will start the time service and synchronize the clocks on CentOS 6.


yum install ntp 
chkconfig ntpd on 
ntpdate pool.ntp.org 
/etc/init.d/ntpd start

		


		

			
						

				Tags: , , .