如何在不失真的情况下打印和显示子进程stdout和stderr输出？

使用来使管道成为非阻塞状态

fcntl.fcntl

select.select

# Helper function to add the O_NonBLOCK flag to a file descriptordef make_async(fd):    fcntl.fcntl(fd, fcntl.F_SETFL, fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK)# Helper function to read some data from a file descriptor, ignoring EAGAIN errorsdef read_async(fd):    try:        return fd.read()    except IOError, e:        if e.errno != errno.EAGAIN: raise e        else: return ''process = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)make_async(process.stdout)make_async(process.stderr)stdout = str()stderr = str()returnCode = Nonewhile True:    # Wait for data to become available     select.select([process.stdout, process.stderr], [], [])    # Try reading some data from each    stdoutPiece = read_async(process.stdout)    stderrPiece = read_async(process.stderr)    if stdoutPiece:        print stdoutPiece,    if stderrPiece:        print stderrPiece,    stdout += stdoutPiece    stderr += stderrPiece    returnCode = process.poll()    if returnCode != None:        return (returnCode, stdout, stderr)

请注意，

fcntl

如果您需要它在不使用Cygwin的Windows上运行，那是可行的，但难度要大得多。您必须：

• 使用pywin32库调用本机Win32 API

• SetNamedPipeHandleState

  与with

  PIPE_NOWAIT

  一起使用以使stdout和stderr管道不阻塞
• 使用

  WaitForMultipleObjects

  而不是

  select

  等待数据可用
• 使用

  ReadFile

  读取数据