Create an animated .gif from existing images using the Gimp

1. Open as Layers. In the open dialog, select the images that will become the frames of the animation
2. Export as .gif

How to remove unprintable characters from a file

cat <file> | tr -dc '[\011\012\015\040-\176]'

Creating a PEM format ssh credentials file

ssh-keygen

openssl rsa -in ./id_rsa -outform pem > ./id_rsa.pem