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 ‘Perl’ Category

Google Cloud Shell: tools, languages and “safe mode”

Posted by jpluimers on 2023/01/19

After publishing Free Linux cloud shell for Gmail users – shell in the browser that works in all locations I’ve been so far, the Google Cloud Shell got extended quite a bit.

There is now [Wayback/Archive] Safe Mode (which skips initialisation scripts):

If there’s a problem in your .bashrc or .tmux.conf files, Cloud Shell immediately close after connection. To resolve this, open Cloud Shell in safe mode by appending cloudshellsafemode=true to the URL. This restarts your Cloud Shell instance and logs you in as root, allowing you to fix any issues in the files.

To permanently delete all files in your home directory and restore your Cloud Shell home directory to a clean state, you can reset your Cloud Shell VM.

And there is support for way more [Wayback/Archive] tools and languages:

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Posted in .NET, C#, Cloud, Development, Go (golang), Google, GoogleCloudShell, Infrastructure, Java, Java Platform, JavaScript/ECMAScript, Node.js, Perl, PHP, Power User, Python, Ruby, Scripting, Software Development | Leave a Comment »

Kristian Köhntopp on Twitter: “Basically, show me a Python regex with \d and without ASCII flag, and I can show you a bug, often exploitable.… “

Posted by jpluimers on 2022/12/14

An interesting thought: [Archive] Kristian Köhntopp on Twitter: “Basically, show me a Python regex with \d and without ASCII flag, and I can show you a bug, often exploitable.… “

Basically, input parsing is still very much underrated by most systems and a constant source of peculiarities and therefore bugs, or phrased differently: [Archive] Kristian Köhntopp on Twitter: “In many cases an uncaught exception, and hence a component crash.… “

Kris also states [Archive] Kristian Köhntopp on Twitter: “Again, Python is not alone in this. Perl, when “use utf8;” is active (which it should) also does this, so every single fucking Regex needs a ‘/a‘ at the end. Nobody ever asked \d to match tengwar or klingon numeric symbols.… “.

The point is in the last few words as Arabic numerals are so white spread over the world that the ten digits 0, 1, 2, 3, 4, 5, 6, 7, 8 , 9 they represent should be the de facto \d pattern, but aren’t in Python as per [Wayback/Archive] re — Regular expression operations — Python 3.10.0 documentation: /d (emphasis mine):

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Posted in Development, Perl, Python, RegEx, Scripting, Software Development | Leave a Comment »

Wake-on-LAN from a Windows machine

Posted by jpluimers on 2022/06/02

Before digging into Wake-on-LAN on Windows machines, I’ll interlude with basically the canonical wakonlan available on many non Windows machines

On Linux and BSD machines, there is the Perl script wakeonlan (steadily at version 0.41) at [Wayback/] jpoliv/wakeonlan: Perl script for waking up computers via Wake-On-LAN magic packets (script: [Wayback/] wakeonlan/wakeonlan at master · jpoliv/wakeonlan) with this help:

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Posted in *nix, *nix-tools, Development, Perl, Power User, Scripting, Software Development, Windows | Leave a Comment »

Zypper: list info on all patterns, so you can find out which pattern provides a package

Posted by jpluimers on 2022/05/11

I wanted to know which pattern provides [WayBack] etckeeper which is in the [WayBack] openSUSE Software package etckeeper.

It seems no built-in search query can do that, so I built one my own.

Since the result takes quite a while to produce, the output is a pattern.txt that you can manually search.

This is the command:

zypper search -t pattern | grep "|" | tail -n +2 | perl -pe 's/^.*? \| //' | perl -pe 's/ *\| .*$//' | xargs -I {} sh -c "zypper info -t pattern {}" > patterns.txt

The content is like this (the 2017 date shows I wrote this a long time ago):

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Posted in *nix, *nix-tools, bash, bash, Development, etckeeper, Linux, Perl, Power User, Scripting, sed, Software Development | Leave a Comment »

PSBL: Passive Spam Block List powered by Spamikaze

Posted by jpluimers on 2018/11/01

On my research list: [WayBackPassive Spam Block List:

PSBL is an easy-on, easy-off blacklist that does not rely on testing and should reduce false positives because any user can remove their ISP’s mail server from the list.

The idea is that 99% of the hosts that send me spam never send me legitimate email, but that people whose mail server was used by spammers should still be able to send me email.

This results in a simple listing policy: an IP address gets added to the PSBL when it sends email to a spamtrap, that email is not identified as non-spam and the IP address is not a known mail server.

Via: Hans Wolters commenting at [WayBack] For my research list: Source: Bruteforce login prevention… – Jeroen Wiert Pluimers – Google+



Posted in *nix, *nix-tools, Development, Perl, Power User, Scripting, Software Development | Leave a Comment »

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