如何检测有人在Linux中打开pty（伪终端）的从属端？

Having more than one process read from a serial device (/dev/ttyXX) makes it so that both processes can't get all of the data -- the data will be split between them in some way. I'd like to write a program that reads from a serial device, creates several master/slave pty pairs, and then allows programs that were made to read from the serial device to instead read from the ptys so that all reading processes receive the data from the serial device and have the ptys act like the serial device in the sense that when they start reading from the pty they get only the most recent data. In other words, you won't get any data that was written before you started to read (it's my experience that this is how /dev/ttyXX devices work, or at least the RS-232 anemometer I'm reading from). Named pipes can mimic these semantics by trapping SIGPIPE to determine that there is no reader and thus we can choose not to write to that particular named pipe. However, some binaries that were written to use terminals may fail when talking to named pipes, as checks for isatty() and the errno condition on calls like tcsetattr() can cause failing conditions. The key here is to be able to use existing binaries that were written for a terminal.Having more than one process read from a serial