get_udp2log_ports.py

def get_udp2log_ports():
    """Returns the listen ports of running udp2log processes"""
    pattern = "/usr/bin/udp2log"
    return [get_p(cmd) for cmd in [get_cmd(pid) for pid in iter_pids()] if has_p(pattern, cmd)]

def has_p(pattern, cmd):
    return pattern in cmd[0] and '-p' in cmd

def get_p(cmd):
    return int(cmd[cmd.index('-p') + 1])

def get_cmd(pid):
    """Get the command-line instantiation for a given process id"""
    with open('/proc/%s/cmdline' % pid, 'rt') as f:
        return f.read().split('\x00')

def iter_pids():
    """Returns an iterator of process ids of all running processes"""
    return (int(node) for node in os.listdir('/proc') if node.isdigit())