Linux

Show wifi password in clear

Got access to a wifi network, but forgot the password? No a problem. At least not if you have a windows, Mac or Linux machine with access. All these OSes can basically without restrictions show you the wifi password in clear text. Windows Once you have access to the wifi network. Open the commandline and enter the following command replacing “SSID” with the actual name of the wifi network you want to retrive the password to.

Cronjob: Basics and reboot

One of Linux five star things is the cronjobs. They allow you to automatically run stuf (scripts, applications, etc.) at quite specific times. The crontab is the place controlling when the stuff is run and you can list the crontab using the commaand crontab -l for the current user. If you want to edit the crontab, just use the command crontab -e and it launches the crontab in the default editor (set EDITOR env variable to change the editor used).

Batch converting JPG and PNG to WebP

I’ve been speed optimizing some of my personal sites, and one easy update is changing the images from being JPEGs and PNG images to the smaller WebP format. All the images I need to convert are usually in collections, where one folder at a time needs conversion and as some contain a lot of images, I needed a way to do it smartly. This is what I came up with:

Automatic MacOS shutdown

From time to time my Mac is doing stuff which takes quite awhile. Converting images, converting videofiles between formats or other stuff, which may take a long time (but reasonable predictable). In those cases I run a little command in the terminal, to automatically shut down the Mac upon completion: sudo shutdown -h +120 This command sets a timer which shutdown the machine after two hours (the 120 parameters being after 120 minutes).

Linux - No space left on device, yet plenty of free space

My little server ran into an issue, and started reporting the error: No space left on device No worries, lest figure out which disk has full and clean up… Using the df command with the -h (for human-readable output) it should be easy to find the issue: root@server:~# df -h Filesystem Size Used Avail Use% Mounted on udev 483M 0 483M 0% /dev tmpfs 100M 3.1M 97M 4% /run /dev/vda 20G 9.