[jitteriest]

Not really important but:

`cat /dev/urandom | tr -dc '0-9' | fold -w 7 | head -n 1`

Can be accomplished in two steps instead of 4:

`tr -dc '0-9' < /dev/urandom | head -c 7`

[gshubert17]

When I tried either of these, on my macOS, I got

tr: Illegal byte sequence

which I got around by changing the locale:

( export LC_ALL=C; tr -dc '0-9' < /dev/urandom | head -c 7 )

with help from: https://unix.stackexchange.com/questions/141420/tr-complains...