> as generated by for example `head -c 30 /dev/urandom | base64 | tr -d '+/='` If you want exactly 30 alphanumeric characters you could do `tr -dc '[:alnum:]'

> as generated by for example `head -c 30 /dev/urandom | base64 | tr -d '+/='` If you want exactly 30 alphanumeric characters you could do `tr -dc '[:alnum:]' < /dev/urandom | head -c 30`