Bytes

$ echo -n 'hello' | fq -d bytes '.[-3:]' > last_3_bytes
$ echo -n 'hello' | fq -d bytes '[.[-2:], .[0:2]] | tobytes' > first_last_2_bytes_swapped

$ echo 'some {"a":1} json' | fq -d bytes '.[5:-6] | fromjson'
{
  "a": 1
}

$ echo 'hello' | fq -d bytes '.[1]'
101