tty

Each serial device shows up twice in /dev , once as a tty.* and once as a cu.* . What is the cu.* device? How does it differ from the tty.* device? mh@maru ~ --> ls -l /dev/*.usbmodem621 crw-rw-rw- 1 root wheel 11, 5 Dec 25 18:00 /dev/cu.usbmodem621 crw-rw-rw- 1 root wheel 11, 4 Dec 25 18:00 /dev/tty.usbmodem621 http://lists.berlios.de/pipermail/gpsd-dev/2005-April/001288.html : The idea is to supplement software in sharing a line between incoming and outgoing calls. The callin device (typically /dev/tty*) is used for incoming traffic. Any process trying to open it blocks within the open()

What exactly does this option do? I've been reading a lot on TTY and am still confused. I played around with not having the -t and just -i and it seems like programs that expect user input throw an error without the -t . Why is it important for pseudo-TTY to be enabled? The "-t" option goes to how Unix/Linux handles terminal access. In the past, a terminal was a hardline connection, later a modem based connection. These had physical device drivers (they were real pieces of equipment). Once generalized networks came into use, a pseudo-terminal driver was developed. This is because it creates a

I noticed there are many mentions of pty and tty in some opensource projects, could someone can tell me what do they mean and what is the difference between them? Thanks! Charlie Martin "tty" originally meant "teletype" and "pty" means "pseudo-teletype". In UNIX, /dev/tty* is any device that acts like a "teletype", ie, a terminal. (Called teletype because that's what we had for terminals in those benighted days.) A pty is a pseudotty, a device entry that acts like a terminal to the process reading and writing there, but is managed by something else. They first appeared (as I recall) for X

I'm seeking for ways to write data to the existing process's STDIN from external processes, and found similar question How do you stream data into the STDIN of a program from different local/remote processes in Python? in stackoverlow. In that thread, @Michael says that we can get file descriptors of existing process in path like below, and permitted to write data into them on Linux. /proc/$PID/fd/ So, I've created a simple script listed below to test writing data to the script's STDIN (and TTY ) from external process. #!/usr/bin/env python import os, sys def get_ttyname(): for f in sys.stdin,

I want to write a simple, dumb, X terminal emulator in C on a Linux system. At first, I just thought I would have to popen a shell and display its output. I checked xterm and rxvt code, and it looks a bit more complicated. First, I have to open a pseudo-terminal with openpty. So I look at the man page and see that openpty fills 2 file descriptors, the master and the slave. Both xterm and rxvt code are messy because of the system-dependent-ness of those specials files. I understand the termios stuff : it's just a bunch of information about the escape code of the terminal. What I really don't

I have a program in Linux which refuses to run if its stdin/stdout is not a TTY (terminal device). Is there an easy-to-use tool which will create a PTY, start the program with the newly created TTY, and copy all data over stdin/stdout? The use case is not interactive, but scripting. I'm looking for the most lightweight solution, preferably not creating TCP connections, and not requiring too many other tools and libraries to be installed. Ignacio Vazquez-Abrams unbuffer , part of expect ( sudo apt-get install expect-dev on Ubuntu Lucid), can fool a program into thinking it's connected to a TTY.