Basic Python's `pexpect` usage routines in interactive process invocation

pexpect-interactive.py

import pexpect

proc = None

def readall():
    data = []
    while True:
        try:
            proc.expect('\n')
            c = proc.before
            if not c: break
            data.append(c)
        except (pexpect.TIMEOUT, pexpect.EOF) as e:
            data.append(proc.before)
            break
    return data

def interact(*params):
    out = []
    for param in params:
        proc.sendline(str(param))
        out.extend(readall())
    out.extend(readall())
    return out

def shell():
    # 0x03 is a Control-C escape code.
    proc.interact('\x03')

if __name__ == '__main__':

    proc = pexpect.spawn(path, timeout=0.1)

    # from now on, one can use:
    # - readall() - to fetch all of the process' stdout (without expect pattern)
    # - interact() - to send input to the process (write into it's stdin), whereas further parameters
    #                 can be combined as follows: interact(param1, param2, ..., paramN)
    # - shell() - to return fully interactive control over the process to the user

Especially handy when it comes to heap-overflow or Use-After-Free exploits, since such process interaction in python may be cumbersome without proper process I/O primitives.