Display an image from stdout [ubuntu]

To send bitcoin from my mobile phone to a plaintext address on my laptop, I like to use QR codes. At first I used websites like qrstuff.com to generate the QR codes, but leaving the command line just to generate and display an image felt like too much of a hassle to me. Then I started using the feh and qrencode utilities in Ubuntu’s package repositories, but that involved creating an image file on my hard drive and then deleting it afterward, which felt messy. So I found a quick and easy way to generate and display a QR code from the command line without creating an intermediate file.