today's howtos

posted by Roy Schestowitz on Jan 06, 2023

• Day 74: using !important in cascade layers

  In order to understand how !important works in cascade layers, you have to understand how !important works generally. The conclusion of this post might not be what you expect.

• Another look at the steps for issuing a cert

  How about we give that a shot now? Let's just go through the steps for getting a secure web site going, and ignore the specifics of the protocol for the moment.

  First, the baseline assumptions: there's a key. There's a certificate signing request which references that key. Then there's the certificate itself with a signature which attaches it to the "web of trust" (ehhh...) that is largely accepted by most clients. Okay?

• Justify Space Between Individual Items in Flexbox

  This is a seemingly trivial thing but I’ve probably looked it up at least three times now, so it’s time to write a blog post about it in hopes that I’ll finally remember the solution.

  tl;dr when aligning a flat hierarchy of items with flexbox, you can use margin: auto to get the effect of justification between individual items.

• S p a m m y s y s c a l l s in strace dumps

  The problem comes when you have a program that has a bunch of stuff to put on the wire, and yet it does it with individual calls to write(). Instead of pushing (say) ~2 KB at the network with a single call, it instead spins through the buffer, writing each one individually. Now you have 2000 packets flying around, all with their headers and everything else as overhead. Having the kernel batch this up is basically saving the world from broken code.

• How to boot on a BTRFS snapshot

  I always wanted to have a simple rollback method on Linux systems, NixOS gave me a full featured one, but it wasn't easy to find a solution for other distributions.

  Fortunately, with BTRFS, it's really simple thanks to snapshots being mountable volumes.

• How To Install CoreFreq on Rocky Linux 9 - idroot

  In this tutorial, we will show you how to install CoreFreq on Rocky Linux 9. For those of you who didn’t know, CoreFreq is a useful tool for monitoring the performance of x86 CPUs and identifying potential issues or bottlenecks. Its real-time monitoring capabilities and support for multiple CPUs make it a valuable tool for system administrators and developers.

  This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation CoreFreq to display real-time information about your CPU performance on Rocky Linux. 9.

• Beginners Guide for Ping Command in Linux

  PING, also known as “Packet Internet Groper,” is the most common networking tool used in Windows, Linux, and macOS to test the connection between the source and the destination.

  The destination, or remote system, could be a web server, your router, or a computer on your local network; you will specify them with their domain or IP address.

  When you specify the destination (domain or IP address), the ping command will send a series of ICMP (Internet Control Message Protocol) packets to the remote system and wait for the response.

  In the response output, you will get different pieces of information using which you can determine whether the remote system is alive or not, the latency of the network, and how many packets are dropped.

  Although you might already be aware of the basic usage of this command, stick with this article to learn several variations and options for the ping command (with examples).

• Beginners Guide for Hash Command in Linux

  You might already be aware of the Linux shell’s default behavior of capturing each user’s executed commands and storing them in the “~/.bash_history” file, so later you can view the history list using the history command.

  Although, history is not the only location where your executed commands are stored, a Linux shell like Bash, Ksh, or Zsh also stores the user’s executed commands in a list known as a hash list.

  In this article, you will learn what the hash list is, the differences between it and the history list, and how to use its command-line tool to manage records in the hash list in Linux.

• How to deploy Apache Tomcat on Ubuntu Server

  Need to serve your java apps from a user-friend web app? Look no further than Tomcat. Find out how to install Tomcat on Ubuntu Linux.