Cannot commuincate with oclHashcat process

[ubtks]

Hello everyone,

I am trying to run oclHashcat as a subprocess in Python. I can start it up just fine, but I cannot pass the usual commands ([s]tatus, [q]uit, etc) by simply writing that character to STDIN.

Code:

import time
import shlex
from subprocess import Popen, PIPE

command = "\"cudaHashcat64.exe\" --quiet -m 0 -a 3 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
proc = Popen(shlex.split(command), stdout=PIPE, stdin=PIPE, stderr=PIPE)

time.sleep(1)

proc.stdin.write("s")

time.sleep(1)

for line in iter(proc.stdout.readline, b''):
    if line:
        if line != "\r\n" and line != "\n":
            print(line)
            proc.stdout.flush()
    else:
        break

proc.terminate()

I should be getting a status response (that will be shown if I remove "--quiet"), but I want to be able to send commands to it. Is oclHashcat not using STDIN and/or only expecting a single character?

I have been googling this for some time, found others that have had a similar issue, and can't view the source to figure it out myself, I would really appreciate any feedback you may have.

Thank you in advanced for any help or ideas!