Binary file padding and splitting.

bin_split.py

#!/usr/bin/env python3

import os
import sys
import time

def doThings(file_name="./sample.jpg", stm32_bufsize=32768, rpi_bufsize=4096, interval=0.0):
    file_size = os.path.getsize(file_name)
    print(f"### Original file size: {file_size} bytes.")

    print("")
    print("### Start padding file:")
    remainder = file_size % stm32_bufsize
    if remainder != 0:
        padding_cnt = stm32_bufsize - remainder
        padding_cmd = "dd if=/dev/zero bs=1 count=" + str(padding_cnt) + " >> " + file_name
        print(f"File padding command is:\n{padding_cmd}")
        os.system(padding_cmd)

    print("")
    print("### Start splitting file into chunks:")
    chunk_cnt = int(os.path.getsize(file_name) / rpi_bufsize)
    for cnt in range(chunk_cnt):
        extract_cmd = "dd skip=" + str(cnt) + " count=1 if=" + file_name + " of=chunk" + str(cnt) + ".bin bs=" + str(rpi_bufsize)
        print(f"File extracting command is:\n{extract_cmd}")
        os.system(extract_cmd)

    print("")
    print("### Start sending file chunks:")
    for cnt in range(chunk_cnt):
        print("chunk" + str(cnt) + ".bin")
        time.sleep(interval)
    
    #os.system("rm chunk*.bin")


if __name__ == "__main__":
    if len(sys.argv) == 5:
        file_name = sys.argv[1]
        stm32_bufsize = int(sys.argv[2])
        rpi_bufsize = int(sys.argv[3])
        interval = float(sys.argv[4])
        doThings(file_name, stm32_bufsize, rpi_bufsize, interval)