Category Archives: Tips & tricks

Beating eval() slowness in Python

Posted on 08.05.2024 by mezzantrop

Turned out, eval() function, which evaluates and executes the specified expression, is dramatically slow in Python, as the compilation is done on the fly. Seeking for a way to enhance the performance, I have stumbled at the Stackoverflow discussion which … Continue reading →

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PAM authentication useful links

Posted on 22.02.2023 by mezzantrop

Sample PAM Application and Sample PAM Conversation Function from FreeBSD documentation Writing Conversation Functions by Oracle example application from The Linux-PAM Application Developers’ Guide

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NoneType issues in chains of inherited dictionaries in Python

Posted on 05.02.2021 by mezzantrop

There are good hints to avoid errors like: in the brilliant Python tips 1: beware of Python dict.get() post.

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A single write locks the entire SQLite database for both: reading and writing

Posted on 08.11.2020 by mezzantrop

This fact is quite an unpleasant thing for a database with a lot of writes and relative seldom reads like, for example, a small packet capturing tool I write for my router. The classical mechanics of SQLite locking is described … Continue reading →

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A quick memo on creating virtual machines using VirtualBox CLI

Posted on 03.08.2020 by mezzantrop

Sorry people, I have to leave it here because at my age I still have trouble organising records in a way that allows me to find notes without being surprised by the cryptic scribbles written on them*. VirtualBox has a … Continue reading →

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Printing lines side by side in shell

Posted on 18.07.2018 by mezzantrop

Everybody knows, there is paste command in every *NIX to print two files side by side or join which is obviously used to join text-files by their key-fields. And there are a lot of examples and tutorials over Internet, so the subject is as … Continue reading →

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A nice way to return string values from functions in Bash

Posted on 27.06.2018 by mezzantrop

What can be as trivial as returning a value from a function in a scripting language? For those who has ever dealt with Bash, the answer turns out to be not so obvious. First, there are multiple options to do … Continue reading →

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Sorting Tumblrs you are following by their last activity

Posted on 16.06.2018 by mezzantrop

It seems, migration to GitLab stimulated me to code more in unusual for me languages and environments. First, it pushed me to do something in PowerShell: A short script to change audit rules on a file or a directory in … Continue reading →

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A short script to change audit rules on a file or a directory in Microsoft Windows

Posted on 13.06.2018 by mezzantrop

Suddenly I have got a lot of work setting audit rules on multiple assorted files on Wintel servers. This short script may help me to do things much quicker. Will check it tomorrow: It requires administrative rights to run. Many thanks https://technochat.in for … Continue reading →

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Quickly report alive IPv6 addresses on the network

Posted on 23.01.2018 by mezzantrop

While searching a robust solution to discover all alive hosts on the local IPv6 subnet, I have found the easiest way except, probably, ndp is to ping … no, not each of them, but the multicast address ff02::1 and then … Continue reading →

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