Pilot Chunk Transfer

Large file transfer with automatic chunking, resume capability, and integrity verification. Use this skill when: 1. You need to transfer files larger than 100MB reliably 2. You want resume capability for interrupted transfers 3. You need integrity verification with checksums per chunk Do NOT use this skill when: - Files are small (<10MB) - use pilot-share for simplicity - You need real-time streaming - use pilot-stream-data instead - You need bidirectional sync - use pilot-sync instead

Large file transfer with automatic chunking, resume capability, and per-chunk integrity verification. Breaks large files into manageable chunks, tracks transfer progress, and enables resuming interrupted transfers.

Commands

Send file with chunking

FILE="/path/to/large-file.iso"
DEST="1:0001.AAAA.BBBB"
CHUNK_SIZE=$((1024 * 1024))  # 1MB

FILENAME=$(basename "$FILE")
FILESIZE=$(stat -f %z "$FILE" 2>/dev/null || stat -c %s "$FILE")
TOTAL_CHUNKS=$(( (FILESIZE + CHUNK_SIZE - 1) / CHUNK_SIZE ))

# Send metadata
pilotctl --json send-message "$DEST" \
  --data "{\"type\":\"chunk_transfer_start\",\"filename\":\"$FILENAME\",\"size\":$FILESIZE,\"total_chunks\":$TOTAL_CHUNKS}"

# Send chunks
for ((i=0; i<TOTAL_CHUNKS; i++)); do
  dd if="$FILE" bs="$CHUNK_SIZE" skip="$i" count=1 2>/dev/null > "/tmp/chunk_$i.dat"
  CHUNK_HASH=$(md5sum "/tmp/chunk_$i.dat" | cut -d' ' -f1)

  pilotctl --json send-message "$DEST" \
    --data "{\"type\":\"chunk_metadata\",\"chunk_id\":$i,\"hash\":\"$CHUNK_HASH\"}"

  pilotctl --json send-file "$DEST" "/tmp/chunk_$i.dat"
  rm "/tmp/chunk_$i.dat"
done

# Send completion
pilotctl --json send-message "$DEST" \
  --data "{\"type\":\"chunk_transfer_complete\",\"filename\":\"$FILENAME\"}"

Receive and reassemble chunks

RECV_DIR="$HOME/.pilot/chunk-recv"
mkdir -p "$RECV_DIR"

INBOX=$(pilotctl --json inbox)
echo "$INBOX" | jq -c '.messages[]' | while read -r msg; do
  TYPE=$(echo "$msg" | jq -r '.type')

  case "$TYPE" in
    chunk_transfer_start)
      FILENAME=$(echo "$msg" | jq -r '.filename')
      mkdir -p "$RECV_DIR/$FILENAME.chunks"
      ;;

    chunk_metadata)
      CHUNK_ID=$(echo "$msg" | jq -r '.chunk_id')
      EXPECTED_HASH=$(echo "$msg" | jq -r '.hash')
      # Verify chunk hash after receiving file
      ;;

    chunk_transfer_complete)
      FILENAME=$(echo "$msg" | jq -r '.filename')
      cat "$RECV_DIR/$FILENAME.chunks"/chunk_* > "$RECV_DIR/$FILENAME"
      rm -rf "$RECV_DIR/$FILENAME.chunks"
      echo "Reassembled: $RECV_DIR/$FILENAME"
      ;;
  esac
done

Resume interrupted transfer

STATE_FILE="/tmp/transfer_state.json"

if [ -f "$STATE_FILE" ]; then
  START_CHUNK=$(jq -r ".\"$FILENAME\".last_chunk // 0" "$STATE_FILE")
else
  START_CHUNK=0
fi

# Continue from START_CHUNK and update state after each chunk

Workflow Example

# Send large file in chunks with resume capability
./pilot-chunk-transfer.sh send /path/to/large.iso 1:0001.AAAA.BBBB

# Receive in background
./pilot-chunk-transfer.sh receive

Dependencies

Requires pilot-protocol skill with running daemon, jq for JSON parsing, dd for chunk extraction, md5sum for integrity verification, and bc for progress calculations.