Pseudoterminal master reads what it has just written

Question

I\'m working on a project that interfaces \"virtual devices\" (python processes) that use serial port connections with real devices that also use serial ports, and I\'m using ps

Answer 1

I'm pretty sure this is because echoing is on by default. To borrow from the Python termios docs, you could do:

master, slave = os.openpty()    # It's preferred to use os.openpty()
old_settings = termios.tcgetattr(master)
new_settings = termios.tcgetattr(master)   # Does this to avoid modifying a reference that also modifies old_settings
new_settings[3] = new_settings[3] & ~termios.ECHO
termios.tcsetattr(master, termios.TCSADRAIN, new_settings)

You can use the following to restore the old settings:

termios.tcsetattr(master, termios.TCSADRAIN, old_settings)