Generate a Chrome extension ID with a desired prefix

gen.sh

#!/bin/bash

# https://stackoverflow.com/a/23877974/3474615

while [[ $EXT_PREFIX != "ioio" ]]  # change 'ioio' to your desired prefix (can only use lowercase a-p)
do
    rm key.pem manifest_key.txt extension_id.txt

    2>/dev/null openssl genrsa 2048 | openssl pkcs8 -topk8 -nocrypt -out key.pem
    2>/dev/null openssl rsa -in key.pem -pubout -outform DER | openssl base64 -A > manifest_key.txt
    2>/dev/null openssl rsa -in key.pem -pubout -outform DER |  shasum -a 256 | head -c32 | tr 0-9a-f a-p > extension_id.txt

    EXT_PREFIX=`cat extension_id.txt | cut -c 4`  # change '4' to the char length of your desired prefix
    cat extension_id.txt
done