The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘ash/dash’ Category

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Open source meme generators on GitHub

Posted by jpluimers on 2026/08/20

I knew open source meme generators would exist, but I never searched for them before. Here is a small table with generator and repository columns:

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Posted in *nix, *nix-tools, ash/dash, bash, bash, Batch-Files, Bookmarklet, CSS, Development, HTML, JavaScript/ECMAScript, Makefile, Power User, Python, Scripting, sh, Sh Shell, Software Development, Web Browsers, Web Development | Leave a Comment »

A bit of perl trickery (or why you don’t should just execute any code you find on-line)

Posted by jpluimers on 2026/07/09

[Wayback/Archive] A bit of perl trickery shows a great example why you should only code you understand.

It explains the innards of a classic trap luring people into execute some obfuscated code, in this case Perl based.

Which makes it yet another testament to not blindly download and execute stuff from the internet.

So be aware when you see obfuscated scripts and things luring you into:

Be even more alert when these require elevated access (like running under sudo).

Via: [Wayback/Archive] Leo Bicknell on Twitter: “@jpluimers @IanColdwater Executes “rm -rf /”. This is ancient Perl monks way of teaching people not to run programs they don’t understand as root. … But hey, these days people “curl -o – url | bash”. It’s surprising that isn’t exploited more.”

Which was response to me asking what the below code did that was fully misunderstood by ChatGPT (which is Large Language Model based on a large corpus of natural language, not a small corpus of evil red-team programming language code snippets) to a series of Tweets by Ian Coldwater.

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Posted in *nix, *nix-tools, ash/dash, bash, bash, CommandLine, Development, Perl, Power User, PowerShell, PowerShell, Python, RegEx, Scripting, sh, Software Development | Leave a Comment »

bash script for $* loop accept command line with spaces in wildcard file names at DuckDuckGo

Posted by jpluimers on 2026/05/05

Back when I wanted a more universal solution [Wayback/Archive] bash script for $* loop accept command line with spaces in wildcard file names at DuckDuckGo I got into a mess of tips that either did not work at all, or were very convoluted.

As back then I only needed a one-time solution, I just listed the filenames with ls into a text file, did some sed and editing steps, then had each file execute in a separate step. Low tech, non-repeatable when new files appeared, but good enough.

In case I want to go for a more universal solution, below are some links to investigate further. Will likely take me hours, so most of the time this is not worth it. Maybe the subshell plus $IFS (Input Field Separators) is a good start, though it gives me a feeling that in the future it will break something else that was expecting a default $IFS value, as is using while read loop. Both types of solutions feel too convoluted. Same for the array solution below.

I might have just been spoiled with PowerShell piping objects instead of strings having made life so much easier.

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Posted in *nix, *nix-tools, ash/dash, bash, bash, Development, Power User, Scripting, Software Development | Leave a Comment »

WireGuard on OpenWRT based GL.iNET: some notes on the `wireguard_watchdog` script

Posted by jpluimers on 2026/01/15

On OpenWRT GL.iNET based devices, the WireGuard client does not restart upon reboot, even if it was started before rebooting.

Hopefully the /usr/bin/wireguard_watchdog script will help with this as others indicates it should.

My first try was no succes, but since it is supposed to run from cron it does no output. The script on GL-SFT1200 firmware version 3.215, script /usr/bin/wireguard_watchdog is different from the one in the OpenWRT repository, so it needs some investigation.

Some links for checking this out:

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Posted in *nix, *nix-tools, ash/dash, ash/dash development, Development, GL-AR300M, GL.iNet, GL.iNET GL-SFT1200, OpenWRT, Power User, Scripting, Software Development | Leave a Comment »

Weather info in plain text or JSON

Posted by jpluimers on 2025/03/06

Two sites that can help you out getting weather info on the console:

wttr.in

wttr.in is developed by [Wayback/Archive] Igor Chubin (@igor_chubin) / X and looks at the request header to figure out what kind of output it sends.

It supports various output formats, so on my TODO list is to see how they do their mapping: always an opportunity to learn (it’s based on Python and Go so I am curious what libraries they use as well).

From the documentation:

wttr.in currently supports five output formats:

  • ANSI for the terminal;
  • Plain-text for the terminal and scripts;
  • HTML for the browser;
  • PNG for the graphical viewers;
  • JSON for scripts and APIs;
  • Prometheus metrics for scripts and APIs.

The ANSI and HTML formats are selected based on the User-Agent string.

There are more parameters in the documentation on the main page of the repository and through this command:

curl wttr.in/:help

The idea is derived from [Wayback/Archive] GitHub – schachmat/wego: weather app for the terminal.

Oh: Igor has more repositories at [Wayback/Archive] chubin (Igor Chubin) · GitHub (including [Wayback/Archive] GitHub – chubin/cheat.sh: the only cheat sheet you need which is hosted at [Wayback/Archive] cheat.sh; I thought I had blogged about that before, but found it only in a draft note mentioning that I got it via [WaybackSave/Archive] Nicolas Krassas on X: “The only cheat sheet you need cheat.sh“)

7timer

A 7 timer JSON usage example is at [Wayback/Archive] Get Weather from 7Timer! · GitHub

It has documentation at

Output formats can be chosen from HTML, PNG, XML and JSON.

Via

[Wayback/Archive] Hacker Public Radio – hpr4266 :: What’s the weather?
Lee writes a script to check what the weather is like ~ The Technology Community Podcast

HPR is a great podcast series!

--jeroen

Posted in *nix, *nix-tools, ash/dash, bash, bash, Development, Go (golang), JavaScript/ECMAScript, JSON, Power User, Python, Scripting, Software Development, Web Development, XML/XSD | Leave a Comment »

ShellCheck – shell script analysis tool

Posted by jpluimers on 2024/02/22

Cool: [Wayback] ShellCheck – shell script analysis tool

ShellCheck finds bugs in your shell scripts

It needs a shebang at the start of a script (like #!/usr/bin/env bash) to recognise the kind of shell, then does amazing analysis.

It is open source at [Wayback/Archive.is] koalaman/shellcheck: ShellCheck, a static analysis tool for shell scripts with excellent documentation including explaining screenshots like

It’s not just available on-line or on the command-line, but also integrates with many code editors (like [Wayback/Archive.is] ShellCheck – Visual Studio Marketplace: Integrates ShellCheck into VS Code, a linter for Shell scripts.) and CI/CD pipelines.

Via: [Wayback] bash – error conditional binary operator expected in compound branch – Unix & Linux Stack Exchange (thanks [Wayback] Cyrus!)

–jeroen

Posted in *nix, *nix-tools, ash/dash, ash/dash development, bash, bash, Development, Power User, Scripting, Software Development | Leave a Comment »

Script to rename a virtual machine in ESXi 6

Posted by jpluimers on 2024/01/10

I bumped into [Wayback/Archive] Script to rename a virtual machine in ESXi 6: gist.github.com/Gremgoll/8bd91258d71fe895c0d416e2543ca2dc.

Then I forked it with the intent to make usage more clear, as the current usage on my ESXi rig (which has mos VMs not in the root of data stores) is like the bold italic portion here:

[root@X9SRI3F-ESXi:/vmfs/volumes/608be754-f21556ad-1082-0025907d9d5c/VM] vm-rename.sh NVMe980PRO_1TB/VM X9SRI-3F-W10P-NL-OFFICE X9SRI-3F-W10P-NL X9SRI-3F-W10P-NL-OFFICE
VOLNAME=NVMe980PRO_1TB/VM
DIRNAME=X9SRI-3F-W10P-NL-OFFICE
OLDNAME=X9SRI-3F-W10P-NL
NEWNAME=X9SRI-3F-W10P-NL-OFFICE
VM_DIRPATH=/vmfs/volumes/NVMe980PRO_1TB/VM/X9SRI-3F-W10P-NL-OFFICE
NW_DIRPATH=/vmfs/volumes/NVMe980PRO_1TB/VM/X9SRI-3F-W10P-NL-OFFICE
Failed to rename './X9SRI-3F-W10P-NL-flat.vmdk' to './X9SRI-3F-W10P-NL-OFFICE-flat.vmdk': The file specified is not a virtual disk (15)
renaming ./X9SRI-3F-W10P-NL-41260b40.vmem to ./X9SRI-3F-W10P-NL-OFFICE-41260b40.vmem
renaming ./X9SRI-3F-W10P-NL-41260b40.vmss to ./X9SRI-3F-W10P-NL-OFFICE-41260b40.vmss
renaming ./X9SRI-3F-W10P-NL-6a4b8f29.hlog to ./X9SRI-3F-W10P-NL-OFFICE-6a4b8f29.hlog
renaming ./X9SRI-3F-W10P-NL.nvram to ./X9SRI-3F-W10P-NL-OFFICE.nvram
renaming ./X9SRI-3F-W10P-NL.vmsd to ./X9SRI-3F-W10P-NL-OFFICE.vmsd
renaming ./X9SRI-3F-W10P-NL.vmx to ./X9SRI-3F-W10P-NL-OFFICE.vmx
renaming ./X9SRI-3F-W10P-NL.vmx.backup to ./X9SRI-3F-W10P-NL-OFFICE.vmx.backup
renaming ./X9SRI-3F-W10P-NL.vmxf to ./X9SRI-3F-W10P-NL-OFFICE.vmxf
renaming ./vmx-X9SRI-3F-W10P-NL-1093012288-1.vswp to ./vmx-X9SRI-3F-W10P-NL-OFFICE-1093012288-1.vswp
All Done. You now need to register X9SRI-3F-W10P-NL-OFFICE to the inventory.

There also was a renaming bug (see the italic line).

I managed to fix both that and added more documentation plus output.

Repositories and code

  1. Original:
  2. Fork with added VSAN functionality (see [Wayback/Archive] Revisions · Script to rename a virtual machine in ESXi 6):
  3. My fork of 2:
  4. My fix:

Code before modifying: [Wayback/Archive] gist.githubusercontent.com/jpluimers/fcc601dd41ac89f601a5174be92c841c/raw/e3683fbb6bdf1e73d65d2b784027c70cf42a5512/vm-rename

Code after modifying: [Wayback/Archive] raw.githubusercontent.com/jpluimers/vm-rename/master/vm-rename.sh.

Yes, that is not in a gist any more (see below why), it is now part of [Wayback/Archive] jpluimers/vm-rename: Script to rename a virtual machine in ESXi 6; fork from https://gist.github.com/jpluimers/fcc601dd41ac89f601a5174be92c841c as [Wayback/Archive] vm-rename/vm-rename.sh at master · jpluimers/vm-rename.

The reason was

Yesterday I described the workaround in Fork Gist to Repo on GitHub – Stack Overflow.

Queries

I found the original via [Wayback/Archive] script esxi rename vmx vmxf and related files – Google Search.

My start was [Wayback/Archive] script esxi duplicate vm and rename vmdk – Google Search which found:

  1. [Wayback/Archive] Renaming a virtual machine and its files in VMware ESXi (1029513) which has a PowerCLI script (that requires Windows to run PowerCLI on)
  2. [Wayback/Archive] Solved: How to clone a VM on a ESXI 6.5 server? – VMware Technology Network VMTN which pointed me to the next Google Search result :
  3. [Wayback/Archive] VMware esxi – Script to clone a VM without vSphere or vCenter. | GrangerX which I put in this gist:
  4. [Wayback/Archive] Script to create Linked Clones on ESXi | RedNectar’s Blog which is great, but way to complicate for my use case. It references a few other cool scripts though, and shows how to use Resource Pools in ESXi (which the Web-UI does not seem to support):
  5. [Wayback/Archive] [script] Cloning VMs using ESXi shell/admin console – Virtualizing Unraid – Unraid
  6. [Wayback/Archive] Script to clone a VM with free VMware ESXi – Rob Pomeroy (again: PowerCLI)

–jeroen

Posted in *nix, *nix-tools, ash/dash, ash/dash development, Development, ESXi6, ESXi6.5, ESXi6.7, Power User, PowerCLI, Scripting, Software Development, Virtualization, VMware, VMware ESXi | Leave a Comment »

VMware ESXi: shell script to get uuid.bios and all Ethernet generatedAddress MAC address values for all VMs

Posted by jpluimers on 2023/12/28

This is a sort of follow-up on ESXi: listing virtual machines with their IP addresses where we ended with this:

I modified the above script to become this:

#!/bin/sh
vmids=`vim-cmd vmsvc/getallvms | sed -n -E -e "s/^([[:digit:]]+)s+((S.+S)?)s+([S+])s+(.+.vmx)s+(S+)s+(vmx-[[:digit:]]+)s*?((S.+)?)$/1/p"`
for vmid in ${vmids} ; do
    # powerState values:
    #   Powered off
    #   Powered on
    #   Suspended
    powerState=`vim-cmd vmsvc/power.getstate ${vmid} | sed '1d'`
    name=`vim-cmd vmsvc/get.config ${vmid} | sed -n -E -e '/(vim.vm.ConfigInfo) {/,/files = (vim.vm.FileInfo) {/ s/^ +name = "(.*)",.*?/1/p'`
    vmPathName=`vim-cmd vmsvc/get.config ${vmid} | sed -n -E -e '/files = (vim.vm.FileInfo) {/,/tools = (vim.vm.ToolsConfigInfo) {/ s/^ +vmPathName = "(.*)",.*?/1/p'`
    # For now, I choose to use only the IPv4 main address from ipAddress, which is in between (vim.vm.GuestInfo) { and net = (vim.vm.GuestInfo.NicInfo) [.
    ipAddress=`vim-cmd vmsvc/get.guest ${vmid} | sed -n -E -e '/(vim.vm.GuestInfo) {/,/net = (vim.vm.GuestInfo.NicInfo) [/ s/^ +ipAddress = "(.*)",.*?/1/p'`
    printf "VM with id %3s has power state %-11s and IPv4=%-15s (name = ${name}; vmPathName = ${vmPathName}).n" "${vmid}" "${powerState}" "${ipAddress}"
done

Now the script grew even larger in to vim-cmd-list-all-VMs-with-IPv4-MAC-uuid.sh:

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Posted in *nix, *nix-tools, ash/dash, ash/dash development, Development, ESXi6, ESXi6.5, ESXi6.7, Power User, Scripting, Software Development, Virtualization, VMware, VMware ESXi | Leave a Comment »

On my list of *n*x things to play with: script and ttyrec

Posted by jpluimers on 2023/01/26

Because of [Archive] PragmaticProgrammers on Twitter: “Helpful Unix trick: use script to log your session. …” / Twitter:

–jeroen

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Posted in *nix, *nix-tools, ash/dash, bash, bash, Batch-Files, Development, Power User, Scripting, Software Development | Leave a Comment »

Don’t fall for the golden hammer: avoid git empty commits, especially for kicking off parts of your CI/CD

Posted by jpluimers on 2022/08/16

A while back Kristian Köhntopp (isotopp) wrote a blog post after quite a Twitter argument where he poses against using git empty commits. I’m with Kris: don’t use them for anything, especially not for kicking off your CI/CD.

Basically his blog post is all about avoiding to think you have a golden hammer, and avoid falling for the Law of the instrument – Wikipedia.

Originally, Abraham Maslow said in 1966:

“I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail.”

For me this has all to do with preventing technical debt: find the right tool to kick your CI/CD pipeline after part of that chain somehow malfunctioned is way better than polluting the commit history with empty commits.

His blog post: [Wayback/Archive.is] Empty commits and other wrong tools for the job | Die wunderbare Welt von Isotopp

The most important bit in it:

And since we are talking about CI/CD pipelines: Don’t YAML them. Don’t JSON them. Don’t XML them.

…

Programming in any of these three is wrong use of tooling, and you should not do it.

  • YAML, JSON and XML are for declarative things.
  • Python, Go and Rust are for procedural things.
  • Bash is for interactive use only.

Use the proper tooling for the job. Be an engineer.

This very much reminds me of an Entwickler Konferenz keynote a long time ago, where Neal Ford made the point that most software engineers act very much unlike what is expected from traditional engineering way of operating where the engineer is both responsible and liable for his actions.

The start of the Twitter thread: [Archive.is] Kristian Köhntopp on Twitter: “A lot of people right now that git is an API and triggering CI/CD pipelines with empty commits replaces the equivalent of a Kubernetes controller for their fragile pile of bash in git triggers. This is broken and begets more brokenness. Evidence:… “

The tweet that started the subtweet: [Archive.is] Florian Haas on Twitter: “(For anyone wondering, what’s nice about this one is it works in any CI. So you don’t have to remember how to manually kick off a GitLab CI pipeline or GitHub Action or Zuul job, you just push an empty commit and off you go.)”

Other relevant tweets:

Yes, you want to avoid shell too (anything like for instance sh, ash, dash, bash or zsh), but you have to know it (and understand why to avoid it) as often it is the only interactive way to access systems from the console.

And of course Kris also wrote a big document on that too, which is available as full PDF (Wayback), full HTML (Wayback) and chaptered HTML Die UNIX Shell /bin/sh.

But more importantly, Kris wrote [Wayback/Archive.is] Using Python to bash | Die wunderbare Welt von Isotopp which is about using Python to do things you might be tempted to do in the shell. It quotes

Shell is a thing you want to understand and then not use, because you learned to understand it.

which is from the German post in thread [Wayback/Archive.is] Bashprogrammierung, wo gehts am besten los which quotes Kris’ 1998 message:

From kris Tue Sep 1 11:26:12 1998
From: kris
Newsgroups: de.comp.os.unix.misc
Subject: Re: Shell-Frage, find, xargs, kopieren von vielen Dateien
References: <6seh24$q9a$2...@nz12.rz.uni-karlsruhe.de>
From: kr...@koehntopp.de (Kristian Koehntopp)
Alignment: chaotic/neutral
X-Copyright: (C) Copyright 1987-1998 Kristian Koehntopp -- All rights
reserved.
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

Marc.Hab...@gmx.de (Marc Haber) writes:
>mir ist das ganze Zeug mit der Shell, find, xargs und Konsorten noch
>reichlich verschlüsselt.

http://www.koehntopp.de/kris/artikel/unix/shellprogrammierung/

>xargs hin oder sollte ich besser ein Perlskript schreiben?

Verwende Perl. Shell will man koennen, dann aber nicht verwenden.

Kristian

–jeroen

Posted in *nix, *nix-tools, ash/dash, ash/dash development, bash, bash, Conference Topics, Conferences, Continuous Integration, Development, DVCS - Distributed Version Control, Event, git, Power User, Scripting, sh, Sh Shell, Software Development, Source Code Management, Technical Debt | Leave a Comment »

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