ShellCheck

Today I learned about ShellCheck, a static analysis tool that “finds bugs in your scripts”. It can and should be run on the command line, but an online version is also available. It catches most style and syntax errors and has plenty of options, like ignoring specific errors and warnings, which is helpful in CI scenarios.

July 24, 2024

How to fix the crontab error `rename: Operation not permitted`

Today, something unexpected happened while I was working on one of our Linux machines. I issued the crontab -e command to add a cron job to my user’s crontab file, modified and saved it, only to the following error: crontab: installing new crontab crontab: crontabs/<user>: rename: Operation not permitted crontab: edits left in /tmp/crontab.hgmsOH/crontab Puzzled, I checked whether my user permissions were all right, if the disk was full, and several other things....

January 25, 2024

rsync with a different user

Today I learned how to rsync with a user different than the one connected to the remote. Why would one want to do such a thing? The data I need to download from that server is owned by ‘backup,’ a different, service-only user. I wanted to avoid going the change-permissions slippery route and allow my user direct access to the data. Looking at the rsync documentation, I learned about the nifty --rsync-path=PROGRAM option:...

August 23, 2023

Troubles with VirtualBox and the Windows Subsystem for Linux

Today I learned the hard way: don’t you dare running a vanilla install of VirtualBox together with Windows Subsystem for Linux v2 (WSL2). It won’t work. That’s because WSL2 uses Hyper-V under the hood, which is incompatible with VirtualBox. According to the official documentation for VirtualBox v6.0: Oracle VM VirtualBox can be used on a Windows host where Hyper-V is running. This is an experimental feature. No configuration is required. Oracle VM VirtualBox detects Hyper-V automatically and uses Hyper-V as the virtualization engine for the host system....

February 14, 2021