run rclone copy/sync/whatever in batches of ≤ N files

batch-process-rclone.sh

# batches of 200 with a ~5-180 seconds delay
# the `cat "{}" >/dev/null &` pre‑caches the vfs, reducing telegram io load and speeding rclone.

find /some/dir -type f -printf '%P\n' -exec sh -xc 'cat "{}" >/dev/null &' \; |
xargs -n200 -d '\n' bash -c '
  printf "%s\n" "$@" |
  rclone -v sync --check-first --transfers 4 -PM --files-from - \
    /some/dir/ some-remote:some/remote/dir/ --error-on-no-transfer &&
  { s=$((RANDOM % 176 + 5)).$RANDOM; echo sleeping $s seconds; sleep $s; }
' _