Questions tagged [tty]
A representation of a device that asynchronously transmits and receives serial data.
816
questions
2
votes
1answer
58 views
How do I successfully run a second X session?
I'm trying to run startx -- :1 vt1 on a tty with a standard user (named stduser), which is already natively logged on Debian 10 with XFCE as per this answer: https://unix.stackexchange.com/a/85384
The ...
2
votes
2answers
107 views
How can I enable TTY console?
I'm running Linux (Debian 10) on a Chromebook (Eve) using a stock Chrome OS kernel (4.4.x) with minor modifications. Everything runs (mostly) fine except that TTY console cannot be accessed via Ctrl+...
3
votes
1answer
32 views
Why is the behavior of the Compose key different under pure console and X?
I'm setting up the keyboard layouts in Xubuntu 20.04.
I generally want to be able to input various Unicode characters, both in pure console and in X, using the same keystrokes. I know that console has ...
0
votes
0answers
25 views
Print Something Before Login [duplicate]
In some distribution installers like Artix Linux Base or Manjaro Linux Architecture installers print a message before the login message. I want to do the same thing. How can I do the same for Linux ...
0
votes
2answers
33 views
Unexpected expect/ssh question
I am seeking to automate ssh password based logins (and a series of actions after logging in).
I am aware that the ssh password prompt bypasses STDIN. To that end I put together a quick expect script.
...
2
votes
1answer
81 views
What's the point of a daemon detaching itself from controlling terminal if the terminal can never be closed?
All sources I've read about writing a daemon say that daemons should detach themselves from controlling terminal so that if the terminal is closed, the daemon won't get SIGHUP.
But daemons are always ...
2
votes
1answer
116 views
What is the relation between tty driver and line discipline
In the famous "The TTY demystified", the following figure is shown:
from which it's seemed that the user process is communicating with the "TTY driver", which in turn communicates ...
0
votes
1answer
43 views
Why is Linux giving a pts number for real terminal console? (which is not an emulated terminal like ssh or xterm)
I read that pts is a pseudo-terminal (that we get through ssh or xterm) and tty is the native terminal.
I didn't connect to my PC through ssh or xterm, but I am still getting pts/0 and pts/1 when I ...
5
votes
3answers
105 views
How can I run a program in its own tty?
I'm messing with TIOCSTI which shoves data into the terminal's input buffer. I want to be able to capture this data before it arrives at the shell or redirects it to a file.
To better illustrate what ...
-1
votes
1answer
31 views
How do terminal emulators receive input from keyboard [closed]
Since terminal emulators are X11 applications, do they receive input from X11Server if we directly type into the corresponding terminal window?
In that case why would /dev/pts/N directory exists?
Do ...
5
votes
2answers
186 views
Where is the terminal view of tty7
When I use ctrl+alt+F7 and switch to the X11 server, I can see the desktop UI.
When I switch to ctrl+alt+[F1-F6], I can see the virtual terminal.
Now how do I access the virtual terminal 7 where I can ...
0
votes
1answer
41 views
Why pseudo-terminals and X write to different special files
Why pseudo-terminal infers keystrokes from /dev/pts/{number}
(and) X-session infers keystrokes from /dev/input/by-id/{keyboard-device-name}?
I understand pseudo-terminal are running on-top of X-...
0
votes
0answers
20 views
/dev/tty7 is not displaying the keyboard inputs
In Ubuntu 14,
Case 1: I entered the following command,
dd if=/dev/tty1 count=2 bs=8
As soon as I enter some characters in tty1 (ctrl+alt+f1), I was able to get some output from above "dd" ...
0
votes
0answers
29 views
void linux boot but doesn't show tty
I installed void-linux without desktop envirement on BISO mode alongside Arch-Linux successfully
I turned on my computer and I choosed Void-GNU/linux from grub it booted
and printed
Loading Linux 5.3....
0
votes
0answers
24 views
Improper Xorg behavior after uninstalling lightdm from Debian Buster
My pc is a i686 personal pc running Debian Buster 10.7 with i3 window manager. Couple days back I uninstalled lightdm hopping to use my terminal tty1 as login manager and perform startx i3 from there ...
0
votes
0answers
24 views
How does non-shell application read input from keyboard [duplicate]
Shell reads the input from keyboard and mouse using the tty attached to it. The same applies for all the programs that I run via command line where the stdin, stdout and stderr are set to console ...
0
votes
0answers
10 views
Core allocation and priority of irq/18-ttyS8
I'm developing an embedded system running RT Linux 5.4. Intel CPU with multiple cores. I need to make sure that my processes run at sufficiently high RT priority on specific cores. However, these ...
0
votes
1answer
76 views
annoying CTRL+F# instead of CTRL+ALT+F# Virtual Terminal Switching on Fedora 33 with sway wayland and gdm
I have the annoying problem that CTRL+F# is switching to a Virtual Terminal. This should normally be done with CTRL+ALT+F# but for some reason it is also triggered by CTRL+F#.
I actually have an ...
0
votes
0answers
46 views
Can I echo to host's local /dev/tty1 with SSH?
I am logged in on a Linux machine. I want to send a message (to a physical screen of the host I'm calling) to be displayed in terminal. Like... chatting with whoever is using this computer at the ...
1
vote
1answer
36 views
TTY = ?, How input is read
When listed down the running processes,
I can see several processes like 'chrome', 'notepad', 'intellij', 'sublime editor' etc.. are having "tty = ?"
Then how are they able to read the ...
0
votes
1answer
20 views
Tty vs User applications
If terminal/console is mapped to a tty (teleTypewriter), then how does other applications like Google chrome, notepad etc.. Read input, output from the keyboard?
0
votes
1answer
57 views
How to set $LS_COLORS variable in TTY
I'm trying to make my console gorgeous with setting custom dircolors. For that I'm doing
eval $(dircolors "dircolors.ansi.dark")
where dircolors.ansi.dark is my custom file with preffered ...
0
votes
0answers
23 views
Anomalous behaviour of tty
The above is the terminal running heroku run bash
I am unable to understand how all of the above are possible at once?
ps shows that controlling terminal is not present, tty shows that stdin is not a ...
1
vote
1answer
25 views
May the screen/keyboard be dedicated to a unique (background/non-root) process?
Consider an industrial computer (say "embedded system"),
equipped with a linux server OS (no desktop)
running just a SINGLE application process (a single non-root user)
attached to an high ...
0
votes
1answer
44 views
Starting 2 different desktop environment on another tty
To give a little background to this question. I am running this on a Raspberry Pi the base OS is Debian Raspbian GNU/Linux 10 (buster), Kernel: Linux 4.19.97-v7l+.
Currently the system boots up and ...
0
votes
0answers
22 views
How to keep Debian tty scrolled to the bottom?
I have a fresh installation of Debian 10. I can access tty1-6 by using ctrl+alt+f1 through f6. When I execute some commands that exceed the number of lines, my screen does not scroll to the bottom, ...
1
vote
1answer
215 views
How to disable login prompt?
I have a VPS, which one can use noVNC to login. I would like to restrict login through ssh only.
Can I remove the portion where it is showing the login prompt? (Preferred to mod this, instead of ...
0
votes
1answer
22 views
Are there tools that I can use to obtain a snapshot of terminal or pty state? [duplicate]
Please stop marking this question as a duplicate, it's not a duplicate. Thanks. Consider the sequence of a, followed by \x1b[D ("cursor back"), followed by b. This would produce an output of ...
0
votes
0answers
20 views
Is it possible to exit `podman run -t` if standard input is redirected?
When I run
podman run -t "" alpine:3 sh
Everything works and is kosher, and I can exit by typing exit, or CONTROL+P, CONTROL+Q. However, if I run
podman run -t "" alpine:3 sh <&...
0
votes
0answers
9 views
tty specification / unit tests
I'm trying to write my own tty system for a Javascript-based operating system.
I found a useful high-level overview of the tty here: What are the responsibilities of each Pseudo-Terminal (PTY) ...
0
votes
0answers
28 views
Synchronous/sequential read/write to tty
I am trying to communicate with a device at /dev/ttyACM0. I need to write one command, and await a response (ACK) before sending the next command.
I found the following article about how to achieve ...
1
vote
1answer
44 views
Sending data to scanner connected via USB to simulate scanned barcode
I have scanner of make Datalogic Magellan 1500i. When I connect it to my machine via USB, I can use the following command to see what barcodes the scanner reads:
cat -v /dev/ttyACM0
F4009900511513^M
...
1
vote
1answer
151 views
How to swap Escape and Caps Lock for tty and X11 [duplicate]
I have done quite a lot of research on how to swap the Escape and Caps Lock keys.
I achieved it while using X11 via my .xinitrc file and the following line of code:
setxkbdmap -option caps:swapescape
...
4
votes
1answer
206 views
Scrolling TTY without dedicated PgUp and PgDown
My keyboard does not have separate PgUp and PgDown keys.
They are in the numpad, sharing their position with KP_9 and KP_3.
Scrolling terminals with Shift+Pg{Up,Down} was not possible either with
...
2
votes
1answer
60 views
How to switch between tty from a shell on a graphic session [duplicate]
I would like to know if it's possible to create an alias (on my .zsh_aliases) to launch a command from the graphical session to a tty (does not matter 1 or 6 ...) ?
I tried with for example cmatrix:
...
0
votes
0answers
20 views
Linux thinks my display is larger than it is, text is cut off on the bottom
I have a HDMI display attached to a Linux system. I am interacting with the system via the command-line using this display.
The GRUB menu looks normal and fits the screen properly, but when it drops ...
0
votes
1answer
43 views
Serial device ttyS0 is missing after configuring BIOS for console redirect
I am running Alpine Linux on a device on which I was making use of a serial console configured on /dev/ttyS0 to login.
I recently enabled console redirection in my BIOS so that I could use the same ...
0
votes
0answers
17 views
Disable a hotkey in agetty
I use a window manager which heavily relies on the super (windows) key. Now, I've got gentoo (agetty, not X session) running in a VM. Whenever I use the super hotkey on the window manager, agetty (VM) ...
0
votes
1answer
35 views
How are the TTY and serial_core related?
I need to write a new character device file for the UART, which allows a few more file operations than usually allowed (not just open, write, etc..)
I'm on an embedded mainline linux kernel (v 5.4).
I ...
0
votes
2answers
39 views
Creating a Bash script to modify tty port permissions
I am trying to create a Bash script that will run on system startup and modify the permissions for a number of ttyA ports. I'm unsure how to go about this and was wondering if I could get some help.
...
0
votes
1answer
49 views
Execute command as if in another open terminal window [closed]
Let's say I have three Terminal windows open:
ttys001: the current terminal I am in. Current directory is ~
ttys002: current directory is ~/Desktop
ttys003: a terminal where I've SSH'd into a remote ...
1
vote
0answers
92 views
How to disable scroll lock for tty terminal
I am working on a command line application that runs from a TTY terminal.
The problem is that whenever the user hits the Scroll Lock key the entire program "freezes" until the user disables ...
0
votes
1answer
38 views
Intel video: crash after running different xorgs on different TTYs
Debian 10 x64
Linux pcname 4.19.0-11-amd64 #1 SMP Debian 4.19.146-1 (2020-09-17) x86_64 GNU/Linux
Intel Core i5-6200U
Intel HD Graphics 520
After being unable to run xorg with startx on TTY1 added /...
1
vote
0answers
36 views
Screen Goes Blank when Changing to Console
Recently I realized that whenever I wanted to change to any of the console windows (Ctrl+Alt+F2 - Ctrl+Alt+F6), my screen simply blanks out and goes into standby due to lack of input from my graphics ...
0
votes
0answers
47 views
Prevent SSH from echoing STDIN when forcing pseudo-TTY
I'm running a command like this:
ssh -tt server "/bin/bash -c \"trap 'kill -HUP 0' EXIT && awk '{print; exit}' > test.txt && ./test.sh\"" <<< "TEST&...
0
votes
0answers
28 views
TTY size with dual monitors
I have two monitors connected with different resolutions (and aspect ratios):
1820x1080 (1.68)
3840x2160 (1.77)
When switching to TTY it's shown on both screens at the same time, with the size (...
5
votes
2answers
867 views
zshrc export GPG_TTY=$(tty) says not a tty
I am trying to set up git commit signing using gpg. I have correctly set up everything. The only problem that I have is when I put export GPG_TTY=$(tty) in my .zshrc and restart a new Konsole window ...
0
votes
1answer
25 views
When I log in, on a tty instance it immediately asks for my sudo password
So I am attempting to log in on a tty, and it looks something like this :
Arch Linux (tty1)
hostname login: _
Password: _
Last Login at (Date) on (tty1)
[sudo] password for user: _
And I think ...
0
votes
0answers
26 views
What termios settings cause endpoint to get garbled serial?
I have two endpoints. One is Windows Subsystem for Linux (Ubuntu) and the other is a small AR9331 router (running OpenWRT and has 16550 chip). They are connected over a USB-to-Serial connection.
...
4
votes
2answers
127 views
program output is different in console and in virtual terminal
when I execute command foo in console (ie tty1), the output is sent to the console.
daemon foo started successfully
When I execute the same command in virtual terminal (terminator), I see no output ...
