koans  C++ 

A few koan-style learning resources for C++

Read 2021-04-14

data structures  hash tables  algorithms  definitions 

Quick summary of the 'hash table' data structure

Read 2021-03-18

Docker  docker-compose  containers  Reference 

Quick reference of some commands to interface with docker directly and/or via docker-compose

Read 2021-03-16

formulas  excel formulas 

Quick reminder for formula to calculate original (full) price when only percent discount and actual (sale) price are known.

Read 2021-03-01

security  GnuPG  SHA256  software integrity  phishing 

Overview on how to verify the integrity of downloaded software prior to installation.

Read 2021-02-23

LibreOffice  LibreOffice Calc  spreadsheets 

How to remove all images in a LibreOffice Calc spreadsheet

Read 2021-02-11

HTTP  web servers  Apache  HTTP 408 

A bit of info about the HTTP 408 Request Timeout error and some reasons why the error occurs.

Read 2021-02-05


How to get the URL of the current page in PHP via the `$_SERVER` superglobal

Read 2020-10-15

Github  git  version control 

Github error when running `git pull origin master`: 'fatal: Couldn't find remote ref master'

Read 2020-10-08

Apache 2.4  Apache (httpd)  linux  web servers  Debian  Debian 10  SSL  mod_ssl 

A quick foray into disabling SSLSessionTickets in Apache2 (because there is no automated key rotation mechanism implemented yet).

Read 2020-09-15

Debian 10  Apache 2.4  Apache  system administration  linux  PHP  PHP-FPM 

How to switch from Apache2 mpm_prefork to mpm_event module and setup php-fpm in Debian 10.

Read 2020-09-15

Apache 2.4  Apache 2  Apache  mod_access_compat  Apache modules  system administration  Apache performance tuning 

Yes, in Apache2.4 the `mod_access_compat` module can safely be disabled, as long as you remove all the deprecated 'Order', 'Allow', and 'Deny' directives from your apache and vhost configs.

Read 2020-09-15

Kubuntu  Kubuntu 19.10  Kubuntu 20.04 

Notes from an in-place upgrade of Kubuntu 19.10 to 20.04

Read 2020-09-02

MariaDB  MySQL  sysadmin 

Syntax reminder: create separate user in mariadb/mysql for remote administration and assign privileges.

Read 2020-09-02

Lenovo  Laptops  Lenovo Carbon X1 (7th gen)  linux 

Notes on using linux with a Lenovo Carbon X1 (7th generation) laptop

Read 2020-09-02