A representation of a device that asynchronously transmits and receives serial data.

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448
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What is the exact difference between a 'terminal', a 'shell', a 'tty' and a 'console'?

I think these terms almost refer to the same thing, when used loosely: terminal shell tty console What exactly does each of these terms refer to?
47
votes
2answers
35k views

Linux: Difference between /dev/console , /dev/tty and /dev/tty0

On a Linux system, what is the difference between /dev/console , /dev/tty and /dev/tty0 ? What is their respective use? How do they compare?
32
votes
2answers
3k views

Can a terminal emulator be as fast as TTY 1-6?

I've been trying various terminal emulators lately, from the built-in gnome-terminal, aterm, xterm, wterm, to rxvt. The test I've been doing is in this order: Open up a tmux window with 2 panes The ...
31
votes
1answer
853 views

What happens when Ctrl + Alt + F<Num> is pressed?

I am looking for an explanation of what happens in Linux when this key combination is pressed to change the current terminal. In particular, what software component intercepts this key combination and ...
26
votes
2answers
22k views

Difference between pts and tty

Possible Duplicate: What is the exact difference between a 'terminal', a 'shell', a 'tty' and a 'console'? I always see pts and tty when I use the who ...
23
votes
4answers
1k views

What are the responsibilities of each Pseudo-Terminal (PTY) component (software, master side, slave side)?

I am trying to figure out how a tty works1 (the work-flow and responsibilities of each elements). I have read several interesting articles about it, but there are still some blurry areas. This is ...
19
votes
6answers
67k views

How to connect to a serial port as simple as using SSH?

Is there a way to connect to a serial terminal just as you would do with SSH? There must be a simpler way than tools such as Minicom, like this $ serial /dev/ttyS0 I know I can cat the output ...
14
votes
2answers
703 views

Can the empty spaces/background in a terminal be replaced with a random(but pretty) pattern of ASCII characters?

Context and Question There are many ways to colorize the terminal and shell environment. The output of individual commands, such as ls and grep, can also be colorized. Not directly related but ...
13
votes
3answers
413 views

Start a process on a different tty

After about an hour of Googling this, I can't believe nobody has actually asked this question before... So I've got a script running on TTY1. How do I make that script launch some arbitrary program ...
12
votes
2answers
2k views

How does a Linux terminal work?

If you fire up a terminal and call an executable (assuming one thats line oriented for simplicity) you get a reply to the command from the executable. How does this get printed to you (the user) does ...
12
votes
2answers
405 views

Possible to configure Login TTY over Audio device (Morse code or similar)?

One of the most miserable aspects of my day job is the need to occasionally investigate problems with machines scattered in remote locations all over the world that don't have network access to the ...
12
votes
1answer
923 views

Screenshot of X from tty

Using Xvfb I can launch an application and take a screenshot. What I'm wondering about is how to capture from an existing (dormant) X session. Say from tty or over ssh. From what I understand ...
11
votes
6answers
9k views

How to stop cursor from blinking

How do I make the cursor stop blinking when in a TTY? (or anywhere else). BONUS Points for one universal setting that stops the cursor blinking almost everywhere.
11
votes
1answer
4k views

TTY On External Monitor

When using my laptop at home, I usually use an external monitor, keyboard, and mouse with my laptop's screen as a second monitor. This is all easily configured using a nice GNOME utility that I ...
10
votes
2answers
6k views

set baud speed for tty

How do I set the baud speed for a specific tty (in this case a serial port)? I tried using stty -F /dev/tty.iap ispeed 19200 But get the error Invalid argument for every speed I try (2400, 4800, ...
10
votes
2answers
227 views

Is there a way to mirror USB outputs?

I'm currently writing a program for a project. It is for a braille reading system where I have a braille display connected via USB that is controlled by a program called brltty. One of the ...
9
votes
1answer
13k views

Is it okay to disable requiretty?

I'm trying to set up a deploy script using Capistrano At a step cap deploy:setup script is connecting to my server and trying to run commands that create directories. Then I see an error: msudo: ...
9
votes
2answers
2k views

Rebinding/disabling CTRL+ALT+F#

I have an application that binds CTRL+ALT+F7, but my linux machine seems to catch the keystroke. Is there a way to rebind/disable this key? A recompile of the kernel is an acceptable answer. The ...
8
votes
3answers
4k views

Why does awk do full buffering when reading from a pipe

I'm reading from a serial port connected to a gps device sending nmea strings. A simplified invocation to illustrate my point: $ awk '{ print $0 }' /dev/ttyPSC9 ...
8
votes
3answers
5k views

How can I hook on to one terminal's output from another terminal?

I need to hook onto output of currently running terminal (tty1) from virtual terminal and capture it (running X server). I'm pretty sure such a thing is possible by simpler means than debugging ...
8
votes
1answer
5k views

How to change tty login prompt?

To be clear, I am not referring to /etc/issue (shown before the prompt) or /etc/motd (shown after login), but the prompt itself, which is currently hostname login: For good measure, I am running ...
8
votes
2answers
3k views

Get ssh to forward signals

I want to be able to send signals (SIGINT is the most important) through ssh. This command: ssh server "sleep 1000;echo f" > foo will start sleep on server and after 1000 seconds it will put ...
8
votes
1answer
2k views

How do I use a font in .ttc format as the console font?

I rather dislike the available tty fonts and would rather use Menlo, which is what I use in OS X's Terminal. Menlo is in a .ttc format, but (from the contents of /usr/share/consolefonts) Linux seems ...
8
votes
2answers
6k views

Poor TTY resolution with nVidia driver

The resolution of the TTY1-6 is poor ~ 640×480 Ubuntu 11.10 | Grub2 | nVidia | NVIDIA GT215 Board I went through the process on this site and after the edit the GRUB menu appears in the correct ...
7
votes
2answers
3k views

Arch Linux how to close tty

I've opened several ttys and I don't know what key combination to use to close a tty. I'm using Arch Linux.
7
votes
1answer
1k views

In which cases is SIGHUP not sent to a job when you log out?

I read an answer from a user who claimed that running foo 2>&1 >& output.log & would result in foo continuing to run even when they log out. According to this user, this even ...
7
votes
1answer
259 views

“w | tail” chops text at right margin (78 characters)

Summary: w | tail chops rows after 78th column. When I run the "w" command, it works as expected. However, when I pipe the output to "tail", it chops the output to 78 columns wide (truncates anything ...
7
votes
2answers
488 views

Are there any linux terminals which can handle all key combinations?

I like to use emacs in terminal mode (-nw), but it seems most (all?) terminals can't handle some key combinations - for example, C-<RET> or C-M-%. I know this is because most terminals emulate a ...
7
votes
1answer
320 views

What exactly is 'scrollback' and 'scrollback buffer'?

What are "scrollback" and "scrollback buffer" in programs like bash and screen, and how do they relate to the tty, the programs being run, and stdin/ stdout/ stderr? Here is the only definition of ...
7
votes
1answer
123 views

How to find which serial port is in use?

The Question: I plugged in a device (i.e. GSM modem) through a serial port (a.k.a. RS-232), and I need to see with which file in /dev/ filesystem this device was tied up, to be able to communicate ...
7
votes
1answer
296 views

What should interactive shells do in orphaned process groups?

(Re-posting in unix per the suggestion in http://stackoverflow.com/questions/13718394/what-should-interactive-shells-do-in-orphaned-process-groups) The short question is, what should a shell do if it ...
6
votes
5answers
3k views

How can I run `watch` as a background job?

When I run: watch 'cmd >> output.txt' & the job gets suspended by the system: 3569 Stopped (tty output) Is there a workaround?
6
votes
2answers
1k views

Detect if running in a virtual terminal?

I'd like to autologin to tty1 on login and then use vlock to lock it. How can I detect from Bash if the current terminal is a console virtual terminal (e.g. tty1), so that I can put the vlock line ...
6
votes
1answer
2k views

Read what is written to /dev/tty*

How can I read what is written to /dev/tty*(* = 0 - number of tty)? I tried sudo tail -f /dev/tty1 on one terminal(X) and then sudo cp .emacs /dev/tty1 from another. X didn't show the the content of ...
6
votes
3answers
1k views

Create Null Modem Pair linux

I am looking to create virtual serial ports on Debian 6 squeeze. Basic requirements are: be able to connect as if port was a real serial port( IE be able to set baud, stop bits etc) com port pairs ...
6
votes
1answer
3k views

Show a notification across all running X displays

Using the command line, I'd like show a notification on every running X display. ( and running console ) Something like: notify-send-all 'Warning' 'Nuclear launch in 5 minutes, please evacuate' Is ...
6
votes
2answers
1k views

Terminate dropped SSH sessions

My SSH sessions seem to be dropping though that is not my major problem - the major problem is my previous sessions are still alive, worse yet one of them is running visudo preventing me from ...
6
votes
1answer
392 views

How to use agetty from the command line

Is it possible to use agetty from the command line? I tried the command sudo agetty -s 34800 tty8 linux but it returns after a few seconds and tty8 is not open. Is it the expected behaviour? Also, ...
5
votes
6answers
1k views

Graphics in TTY

Something has come up which demands me to work only in command line. My primary job is programming (mostly in Fortran and Octave) and I need to display plots. As a lame example: I open octave and ...
5
votes
2answers
578 views

My process was killed but I cannot understand the kernel notice

I have a custom application running on an embedded x86 setup (built using buildroot and uClibc). The application has been running fine but this morning when I returned to work I discovered my process ...
5
votes
1answer
942 views

Return to X session after Ctrl+Alt+F1

What is the command to return to the graphical desktop after entering the terminal mode with Ctrl+Alt+F1? I need it for operating my Raspbian.
5
votes
3answers
2k views

How to clear terminal after logging out?

Currently on my laptop when I log out I can still see traces of my last activities (in tty). How can I tell it (Gentoo) to clear the screen before logging out?
5
votes
4answers
16k views

Pseudo-terminal will not be allocated because stdin is not a terminal

I'm trying to set up automatic SSH hopping through a server which doesn't have nc. This works from the command line: ssh -A gateway ssh steve@target (I have added my public key to the SSH agent). ...
5
votes
3answers
748 views

Construct a command by putting a string into a tty

I managed to do this echo -n "command" > /dev/tty1 The letters appear, and the cursor moves, but they are "ghosts" - if you hit enter, nothing happens (they are not in stdin). Edit: In the ...
5
votes
2answers
19k views

Can I change the font of terminal?

I have a Un*x OS installed without desktop, I wonder if it is possible to change the font of terminal.
5
votes
2answers
865 views

Best way to set serial port speeds on boot?

I've got instruments hooked up to /dev/ttyS1 through ttyS9 on a machine running Debian Wheezy. The various instruments communicate at various speeds. Is there a better way to set the baud rates than ...
5
votes
1answer
123 views

How do I ensure that a terminal remains scrollable?

On my tty terminals (1-6), I lose text when I move away from it and back (i.e. pressing ShiftPg Up doesn't reveal any scrolled-off text). How can I recover this text?
5
votes
2answers
1k views

Why are there so many virtual terminal devices?

I've been reading the Advanced Linux Programming book and it mentions about virtual terminals which, if I understood it correctly, it is a Linux-specific feature (not in Unix) to allow multiple login ...
5
votes
2answers
765 views

How can I launch applications from 2 ttys on launch?

I've currently got 2 ttys logging in automatically, but I need to launch a node script from one and a C program from another as soon as the device loads. The device is a Raspberry Pi running ...
5
votes
1answer
2k views

Cannot switch to TTYs or back

I just upgraded to Mint 13 - KDE x64 I am unable to switch to ttys by using the CtrlAltF1 .. F6 keys. The gettys are running and I can switch to the terminals with the sudo chvt 1 command. I have ...