Eureka! · Personal micro-blog where I write about new interesting things that I learn about (and which I bother writing down)

ImageMagick is a well-known CLI tool that provides image processing capabilities. It can handle hundreds of different image formats and gives you a programmatic interface to create, edit, compose, and convert images. I personally use the convert command very often to resize an image (e.g., convert -resize 300x300 -quality 100 source.png out.png) or convert between different formats. ImageMagick also has the ability to produce a visual diff between two images, by using its compare & montage commands.

SNI (Server Name Indication) is an extension to the TLS protocol, introduced in 2003. It allows for a single server (or rather IP address) to host more than one domain and accept encrypted traffic for these.

jq --slurp conflates multiple JSON document inputs into a single array. This allows you to run a jq filter only once for all inputs, instead of once per document.

comm is a command line tool that allows you to compare two sorted files, line by line.