hidcat.py

#!/usr/bin/env python3

def usage():
  p = os.path.basename(sys.argv[0])
  return f"""
{p} - Cat USB HID device input
Usage: {p} -a bus.dev [-i ifnum]
Example:
  $ {p} -a 1.31
""".lstrip()

def help():
  sys.stderr.write(usage())
  sys.exit(0)

import os
import sys
import hid
import re

from argparse import ArgumentParser

def list():
  for i in hid.enumerate():
    print(i)

def find_path(opt):
  bus, dev = map(lambda v: int(v, 0), re.split('[.:]', opt.address))
  return f"{bus:04x}:{dev:04x}:{opt.interface:02x}".encode()

def main(opt):
  path = find_path(opt)

  dev = hid.device()
  dev.open_path(path)
  dev.set_nonblocking(1)

  while True:
    buf = dev.read(64, 100)
    if buf:
      sys.stdout.buffer.write(bytes(buf))
      sys.stdout.buffer.flush()

if __name__ == '__main__':
  ap = ArgumentParser()
  ap.print_help = help
  ap.add_argument('-a', '--address')
  ap.add_argument('-i', '--interface', default=0)
  ap.add_argument('args', nargs='*')
  opt = ap.parse_args()

  if opt.address is None:
    help()

  main(opt)