Python fcntl.F_GETFL Examples

def blocking(self, port, mode=False):
        """
        Set port function mode blocking/nonblocking

        :param port: port to set mode
        :param mode: False to set nonblock mode, True for block mode
        """
        fd = self._open([port])[0]

        try:
            fl = fcntl.fcntl(fd, fcntl.F_GETFL)
            if not mode:
                fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
            else:
                fcntl.fcntl(fd, fcntl.F_SETFL, fl & ~os.O_NONBLOCK)

        except Exception as inst:
            print("FAIL: Setting (non)blocking mode: " + str(inst))
            return

        if mode:
            print("PASS: set to blocking mode")
        else:
            print("PASS: set to nonblocking mode") 

def set_blocking(fd, blocking=True):
    """
    Set the given file-descriptor blocking or non-blocking.

    Returns the original blocking status.
    """

    old_flag = fcntl.fcntl(fd, fcntl.F_GETFL)

    if blocking:
        new_flag = old_flag & ~ os.O_NONBLOCK
    else:
        new_flag = old_flag | os.O_NONBLOCK

    fcntl.fcntl(fd, fcntl.F_SETFL, new_flag)

    return not bool(old_flag & os.O_NONBLOCK) 

def __init__(self, command):
        """
        Creates an interactive process to interact with out of a command

        :param str command: the command to be executed
        """

        from fcntl import fcntl, F_GETFL, F_SETFL
        from subprocess import Popen, PIPE
        import os

        self._command = command
        self._executable = command.split(" ", 1)[0]

        _Log.debug("Starting the interactive process: {}".format(command))

        self._process = Popen(command, shell=True, stdout=PIPE, stdin=PIPE,
            stderr=PIPE)
        fcntl(self._process.stdin, F_SETFL,
            fcntl(self._process.stdin, F_GETFL) | os.O_NONBLOCK)
        fcntl(self._process.stdout, F_SETFL,
            fcntl(self._process.stdout, F_GETFL) | os.O_NONBLOCK)
        fcntl(self._process.stderr, F_SETFL,
            fcntl(self._process.stderr, F_GETFL) | os.O_NONBLOCK) 

def __init__(self, pScene):
        self.pScene = pScene
        #self.infile_path = "/dev/input/event" + (sys.argv[1] if len(sys.argv) > 1 else "0")
        self.infile_path = "/dev/input/event0"
        self.FORMAT = 'llHHI'
        self.EVENT_SIZE = struct.calcsize(self.FORMAT)
        self.lastPtX = 0
        self.lastPtY = 0
        self.rateX = float(480) / 3900
        self.rateY = float(320) / 3900
        self.sep = 0
        #print str(rateX)
        #print str(rateY)
        self.in_file = open(self.infile_path, "rb")
        flag = fcntl.fcntl(self.in_file, fcntl.F_GETFL)
        fcntl.fcntl(self.in_file, fcntl.F_SETFL, os.O_NONBLOCK) 

def set_nonblock(self, set_flag=True):
        """Set the non blocking flag on the socket"""

        # Get the current flags
        if self.fd_flags is None:
            try:
                self.fd_flags = fcntl.fcntl(self.ins, fcntl.F_GETFL)
            except IOError:
                warning("Cannot get flags on this file descriptor !")
                return

        # Set the non blocking flag
        if set_flag:
            new_fd_flags = self.fd_flags | os.O_NONBLOCK
        else:
            new_fd_flags = self.fd_flags & ~os.O_NONBLOCK

        try:
            fcntl.fcntl(self.ins, fcntl.F_SETFL, new_fd_flags)
            self.fd_flags = new_fd_flags
        except Exception:
            warning("Can't set flags on this file descriptor !") 

def read_char_no_blocking():
    ''' Read a character in nonblocking mode, if no characters are present in the buffer, return an empty string '''
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    old_flags = fcntl.fcntl(fd, fcntl.F_GETFL)
    try:
        tty.setraw(fd, termios.TCSADRAIN)
        fcntl.fcntl(fd, fcntl.F_SETFL, old_flags | os.O_NONBLOCK)
        return sys.stdin.read(1)
    except IOError as e:
        ErrorNumber = e[0]
        # IOError with ErrorNumber 11(35 in Mac)  is thrown when there is nothing to read(Resource temporarily unavailable)
        if (sys.platform.startswith("linux") and ErrorNumber != 11) or (sys.platform == "darwin" and ErrorNumber != 35):
            raise
        return ""
    finally:
        fcntl.fcntl(fd, fcntl.F_SETFL, old_flags)
        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings) 

def train(self):
        i=0
        if(self.args.ipython):
            import fcntl
            fd = sys.stdin.fileno()
            fl = fcntl.fcntl(fd, fcntl.F_GETFL)
            fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)

        while((i < self.total_steps or self.total_steps == -1) and not self.gan.destroy):
            i+=1
            start_time = time.time()
            self.step()
            GlobalViewer.tick()

            if (self.args.save_every != None and
                self.args.save_every != -1 and
                self.args.save_every > 0 and
                i % self.args.save_every == 0):
                print(" |= Saving network")
                self.gan.save(self.save_file)
            if self.args.ipython:
                self.check_stdin()
            end_time = time.time() 

def _setup_pipe(self, name):
        real_fd = getattr(sys, '__%s__' % name).fileno()
        save_fd = os.dup(real_fd)
        self._save_fds[name] = save_fd
        
        pipe_out, pipe_in = os.pipe()
        dup2(pipe_in, real_fd)
        os.close(pipe_in)
        self._real_fds[name] = real_fd
        
        # make pipe_out non-blocking
        flags = fcntl(pipe_out, F_GETFL)
        fcntl(pipe_out, F_SETFL, flags|os.O_NONBLOCK)
        return pipe_out 

def set_binary_mode(f):
            try:
                fileno = f.fileno()
            except Exception:
                pass
            else:
                flags = fcntl.fcntl(fileno, fcntl.F_GETFL)
                fcntl.fcntl(fileno, fcntl.F_SETFL, flags & ~os.O_NONBLOCK)
            return f 

def setUpClass(cls):
        cls.readFd,  w = os.pipe()
        flags = fcntl.fcntl(cls.readFd, fcntl.F_GETFL, 0)
        fcntl.fcntl(cls.readFd, fcntl.F_SETFL, flags | os.O_NONBLOCK)
        os.dup2(w, 2) 

def pause(secs):
    fd = sys.stdin.fileno()

    oldterm = termios.tcgetattr(fd)
    newattr = termios.tcgetattr(fd)
    newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
    termios.tcsetattr(fd, termios.TCSANOW, newattr)

    oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
    fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)

    try:
        ctrlc = False
        paused = False
        t = secs / 0.1
        i = 0
        while i < t:
            if keypressed():
                paused = True
                break
            sleep(0.1)
            i += 1

        if paused:
            while True:
                if keypressed():
                    break
                sleep(0.1)
    except KeyboardInterrupt:
        ctrlc = True

    termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
    fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)
    if ctrlc:
        sys.exit(1) 

def process(self,filename):

        process = subprocess.Popen(
            self.tail_command + [filename], stdin=subprocess.PIPE,
            stdout=subprocess.PIPE, stderr=subprocess.PIPE
        )
    
        # set non-blocking mode for file
        function_control = fcntl.fcntl(process.stdout, fcntl.F_GETFL)
        fcntl.fcntl(process.stdout, fcntl.F_SETFL, function_control | os.O_NONBLOCK)
    
        function_control = fcntl.fcntl(process.stderr, fcntl.F_GETFL)
        fcntl.fcntl(process.stderr, fcntl.F_SETFL, function_control | os.O_NONBLOCK)
        
        return process 

def isNonBlocking(skt):
    """
    Determine if the given socket is blocking or not.

    @param skt: a socket.
    @type skt: L{socket.socket}

    @return: L{True} if the socket is non-blocking, L{False} if the socket is
        blocking.
    @rtype: L{bool}
    """
    return bool(fcntl.fcntl(skt.fileno(), fcntl.F_GETFL) & os.O_NONBLOCK) 

def _setup_pipe(self, name):
        real_fd = getattr(sys, '__%s__' % name).fileno()
        save_fd = os.dup(real_fd)
        self._save_fds[name] = save_fd
        
        pipe_out, pipe_in = os.pipe()
        dup2(pipe_in, real_fd)
        os.close(pipe_in)
        self._real_fds[name] = real_fd
        
        # make pipe_out non-blocking
        flags = fcntl(pipe_out, F_GETFL)
        fcntl(pipe_out, F_SETFL, flags|os.O_NONBLOCK)
        return pipe_out 

def _set_nonblocking(fd):
        flags = fcntl.fcntl(fd, fcntl.F_GETFL)
        flags = flags | os.O_NONBLOCK
        fcntl.fcntl(fd, fcntl.F_SETFL, flags) 

def start_second_deployd(context):
    context.daemon1 = Popen("paasta-deployd", stderr=PIPE)
    output = context.daemon1.stderr.readline().decode("utf-8")
    fd = context.daemon1.stderr
    fl = fcntl.fcntl(fd, fcntl.F_GETFL)
    fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
    for i in range(0, 5):
        try:
            output = context.daemon1.stderr.readline().decode("utf-8")
            print(output.rstrip("\n"))
            assert "This node is elected as leader" not in output
        except IOError:
            pass
        time.sleep(1) 

def _set_nonblocking(fd):
    flags = fcntl.fcntl(fd, fcntl.F_GETFL)
    fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) 

def _set_nonblocking(self, fd):
        flags = fcntl.fcntl(fd, fcntl.F_GETFL)
        fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) 

def session_start(self):
        self._log("SESSION_START")
        self.process = subprocess.Popen(SHELL, shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, preexec_fn=os.setsid)

        flags = fcntl.fcntl(self.process.stdout, fcntl.F_GETFL)
        fcntl.fcntl(self.process.stdout, fcntl.F_SETFL, flags | os.O_NONBLOCK) 

def make_non_blocking(file_io):
  fd = file_io.fileno()
  fl = fcntl.fcntl(fd, fcntl.F_GETFL)
  fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK) 

def flag_string(fd):
    """flag_string(fd)
    where fd is an integer file descriptor of an open file. Returns the files open
    flags as a vertical bar (|) delimited string.
    """
    flags = fcntl.fcntl(fd, fcntl.F_GETFL)
    strlist = filter(None, map(lambda n: (flags & getattr(os, n)) and n, os.OLIST))
    # hack to accomodate the fact that O_RDONLY is not really a flag...
    if not (flags & os.ACCMODE):
        strlist.insert(0, "O_RDONLY")
    return "|".join(strlist)


# XXX still need to verify this or add more. 

def _set_nonblocking(fd: int) -> None:
    flags = fcntl.fcntl(fd, fcntl.F_GETFL)
    fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) 

def _set_nonblocking(fd: int) -> None:
    flags = fcntl.fcntl(fd, fcntl.F_GETFL)
    fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) 

def _set_nonblocking(self, fd):
        flags = fcntl.fcntl(fd, fcntl.F_GETFL)
        fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) 

def _set_nonblocking(fd):
    flags = fcntl.fcntl(fd, fcntl.F_GETFL)
    fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) 

def _remove_nonblock_flag(self, fd):
            flags = fcntl.fcntl(fd, fcntl.F_GETFL) & (~os.O_NONBLOCK)
            fcntl.fcntl(fd, fcntl.F_SETFL, flags) 

def make_nonblocking(fd):
        """Put the file descriptor *fd* into non-blocking mode if possible.

        :return: A boolean value that evaluates to True if successful."""
        flags = fcntl.fcntl(fd, fcntl.F_GETFL, 0)
        if not bool(flags & os.O_NONBLOCK):
            fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK)
            return True 

def test_setBlocking(self):
        """
        L{fdesc.setBlocking} sets a file description to blocking.
        """
        r, w = os.pipe()
        self.addCleanup(os.close, r)
        self.addCleanup(os.close, w)
        fdesc.setNonBlocking(r)
        fdesc.setBlocking(r)
        self.assertFalse(fcntl.fcntl(r, fcntl.F_GETFL) & os.O_NONBLOCK) 

def test_setNonBlocking(self):
        """
        L{fdesc.setNonBlocking} sets a file description to non-blocking.
        """
        r, w = os.pipe()
        self.addCleanup(os.close, r)
        self.addCleanup(os.close, w)
        self.assertFalse(fcntl.fcntl(r, fcntl.F_GETFL) & os.O_NONBLOCK)
        fdesc.setNonBlocking(r)
        self.assertTrue(fcntl.fcntl(r, fcntl.F_GETFL) & os.O_NONBLOCK) 

def set_fd_status_flag(fd, flag):
    """Set a status flag on a file descriptor.

    ``fd`` is the file descriptor or file object, ``flag`` the flag as integer.

    """
    flags = fcntl.fcntl(fd, fcntl.F_GETFL, 0)
    fcntl.fcntl(fd, fcntl.F_SETFL, flags | flag)