SOME_COMMAND() { cat; }
input_for_SOME_COMMAND() {
local index mainCommand
index=$1; shift || return
for arg; do
printf '%s\n' "$arg" "$((index++)) sub$arg"
done
}
SOME_COMMAND <<<"$(input_for_SOME_COMMAND 1 subcommand{1,2,3,4,5})"
U09NRV9DT01NQU5EKCkgeyBjYXQ7IH0KCmlucHV0X2Zvcl9TT01FX0NPTU1BTkQoKSB7CiAgbG9jYWwgaW5kZXggbWFpbkNvbW1hbmQKICBpbmRleD0kMTsgc2hpZnQgfHwgcmV0dXJuCiAgZm9yIGFyZzsgZG8KICAgIHByaW50ZiAnJXNcbicgIiRhcmciICIkKChpbmRleCsrKSkgc3ViJGFyZyIKICBkb25lCn0KClNPTUVfQ09NTUFORCA8PDwiJChpbnB1dF9mb3JfU09NRV9DT01NQU5EIDEgc3ViY29tbWFuZHsxLDIsMyw0LDV9KSIK