screenqr.sh

#!/usr/bin/env bash

# Interactively capture a screenshot (using the cursor), and decode any 1D or 2D
# barcodes in the image (such as QR Code, EAN-13, etc...)
#
# OS X / macOS only
# Requires:
#   - zbar (http://zbar.sourceforge.net/, `brew install zbar`)
#   - screencapture (included with the system)
function screenqr() {
    for cmd in zbarimg screencapture; do
        type "$cmd" >/dev/null 2&>1 || {
            echo "$0: '$cmd' is required but could not be found. Exiting." >&2
            return 1
        }
    done

    tmpfile=$(mktemp)
    screencapture -i "$tmpfile" && zbarimg --quiet "$tmpfile"
    rm "$tmpfile"
}