Hostname bruteforcing on the cheap

Quick update: As @MikeDamm points out, xargs has a -P option that can do the same thing I’m using parallel for. If you have a supported version of xargs you can use -P 0 to do the same thing as -j0 with parallel, but if your version doesn’t support the 0 you can simply use the same number parallel uses ala: cat subdomains.txt | xargs -P 122 -I subdomain dig +noall subdomain.