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

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702
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5answers
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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?
34
votes
4answers
5k 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 ...
8
votes
3answers
2k 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 ...
14
votes
2answers
53k views

Can I change the font of terminal?

I have a Unix-like OS installed without desktop. Is it possible to change the font of the terminal?
8
votes
4answers
549 views

ls command operating differently depending on recipient

How does commands like ls know what its stdout is? It seems ls is operating different depending on what the target stdout is. For example if I do: ls /home/matt/tmp the result is: a.txt b.txt c....
5
votes
1answer
788 views

How do I come by this pty and what can I do with it?

It seems that a simple shell redirect from /dev/ptmx gets me a new pseudo-terminal. $ ls /dev/pts; ls /dev/pts </dev/ptmx 0 1 2 ptmx 0 1 2 3 ptmx It disappears as soon as the process that ...
46
votes
2answers
49k 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 command ...
43
votes
2answers
5k 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 ...
8
votes
3answers
5k 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 ...
81
votes
2answers
64k 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 and how do they compare?
33
votes
9answers
143k 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 ...
33
votes
1answer
1k 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 ...
4
votes
2answers
3k views

256 color in Linux console

I have in my .bashrc export TERM=xterm-256color but this cause blinking all colored text (ls --color, in vim etc.) in a Linux console (Ctrl+Alt+F1). So is there any possibility to recognize in ...
4
votes
5answers
1k views

Multiple terminals at once without an X server

There is a way to visualize multiple terminals at the same time without running a Xorg session ? I have a really low profile machine that could be great for some basic stuff but has an horrible ...
0
votes
1answer
149 views

NixOS no login prompt in virtual terminals

I have NixOS built using 15.09 channel, session manager is sddm, display manager is KDE 5. Switching to virtual ttys from 1 to 6 gives me no login prompt, I see same piece of log everywhere: <<...
0
votes
1answer
150 views

How are virtual consoles related to traditional computer terminals?

This is extracted (with some rewording) from Computer terminal and virtual console, which has been closed with a hatnote linking to What is the exact difference between a 'terminal', a '...
18
votes
2answers
6k 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 ...
6
votes
1answer
37k views

How to read/write to tty* device?

I have a device that sends information over USB to my computer. Arch Linux sets up this device by creating a file named ttyUSB0 in /dev/. I have been using GTKterm to receive this incoming information ...
8
votes
4answers
33k 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). ...
14
votes
7answers
15k 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.
12
votes
1answer
3k 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 "...
9
votes
1answer
350 views

Make program in a pipe think it has tty

Test environment: $ mkdir testdir $ cd testdir $ echo | tee "file name" Now, ls will print file?name (under Ubuntu GNU bash, at least), while ls | cat will print file and name in separate lines. ...
6
votes
1answer
19k views

Change the number of rows and columns in the TTY [duplicate]

I want to resize the terminal which comes up when you press CtrlAltF1 (or F2,F3,...). 25x80 is small for a 24" screen. Tried using stty, but the commands stty columns 200 and stty rows 50 does not ...
7
votes
1answer
6k 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 ....
5
votes
1answer
140 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?
2
votes
1answer
199 views

How can I live-change the TTY rows and columns?

This is a question about Linux running on a Compulab device named Utilite Pro, but I think it is worth the price to ask this question here to get it solved for any platform (if possible). I use ...
2
votes
1answer
193 views

Why does `last` show '{' and '|' in the TTY field?

We recently set up a new FreeBSD 7.2 machine on March 11. When looking at last, we noticed some funny characters for the TTY field. What do these characters mean? Note that at this time, the ...
-2
votes
2answers
915 views

Corresponding 7zip command for unzip -p -a

I have a question regarding unzip command in Unix. As of now my Unix command unzip -p -a is able to zip the file which are lesser in size. But if the file size is larger then the command is not able ...
20
votes
6answers
25k 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 (...
16
votes
2answers
1k 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 ...
8
votes
1answer
2k 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 ...
17
votes
1answer
29k 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: ...
13
votes
3answers
4k 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 ...
10
votes
3answers
1k 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 ...
8
votes
1answer
536 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 ...
17
votes
5answers
5k 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 'f\...
3
votes
1answer
3k views

Change the number of generated /dev/tty devices

I'm building an embedded Linux system, based on Gentoo. Using udev, all tty devices are probed with a PROGRAM stanza to determine if they are a modem. Right now the system boots up with 64 /dev/tty*. ...
6
votes
2answers
877 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
4k views

How can you get console backgrounds for Arch Linux?

I have tested out openSUSE and found that the tty1 is a bit different from other systems as the tty has got a background. I know that Knoppix has a tux penguin for each core the computer has, but I'm ...
3
votes
2answers
557 views

Print console colors

Wrote a bash function to display the console colors. But, it seems some of the colors are not possible to show that way! (?) Also, note the strange "bright black"! (Note: The below screendump is of ...
2
votes
1answer
69 views

Return to GUI from text console with many X11 servers?

I know the thread How to get out of TTY and into X session apparently about similar thing as here, and Command line to return to the GUI after Ctrl-Alt-F1 about chvt. I have Ubuntu 14.04 LTS. I run ...
2
votes
2answers
272 views

Take copy of TTY0 text

I have some output in TTY1 that I think might hold clues as to why my last GUI session froze (CtrlAltBackspace was able to get me back to the terminal and I reloaded the GUI). However, I cannot seem ...
1
vote
1answer
208 views

Why does tapping a TTY device only capture every other character?

So, I came across the ttyname function (unistd.h) and had to test it out. #include <unistd.h> #include <stdio.h> int main(void) { printf("%s\n", ttyname(0)); return 0; } On my ...
9
votes
3answers
7k 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 GPGGA,073651.000,6310.1043,N,...
6
votes
1answer
1k views

Debian chroot blocking PTTYs on host

I've created a Debian-based chroot environment using debootstrap under Arch Linux, and fill it with life like this: #!/bin/sh mount -t proc proc $CHROOT/proc mount -t devpts devpts $CHROOT/dev/pts ...
6
votes
2answers
2k 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 Raspbian....
4
votes
2answers
635 views

How to get the real name of the controlling terminal?

How can one get the real name of the controlling terminal (if there is one, else an error) as a pathname? By "real name", I mean not /dev/tty, which cannot be used by other arbitrary processes to ...
3
votes
1answer
3k views

How can I pipe commands to any terminal?

I often use more than one terminal (or terminal emulator) at a time; and while in X I can copy-paste commands, besides not being very practical, it obviously does not work on the real TTY. The first ...
3
votes
1answer
694 views

What is the maximum allowed number of TTY, is it defined anywhere in kernel headers?

What's the maximum allowed number of TTYs? I found pty.max, but is there anything similar for TTYs? Or is it defined as a fixed value in kernel headers, I couldn't find that
3
votes
1answer
2k views

No room on ep ring?

I just switched to tty1, and I'm getting all kinds of output. It all looks like this: [timestamp] xhci_hcd 0000:00:14.0: ERROR no room on ep ring It's happening over 100 times per second, every 5 ...