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Questions tagged [tty]

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

11
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0answers
414 views

Why does my terminal letter-spacing decrease when I disable a display return from using /dev/tty?

I've got a curious hardware situation, and I've run into a curious software quirk. I have a laptop with a broken screen that I have hooked up to an external display. I start up an X session and open a ...
4
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0answers
166 views

What exactly in the sudo behavior is unpredictable?

In the Best practices for writing Dockerfiles guide of the docker documentation, we can read: Avoid installing or using sudo since it has unpredictable TTY and signal-forwarding behavior that can ...
4
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0answers
973 views

How can I start an LXC (linux container) X server on separate TTY?

Apart from my default X server, which I run on tty1, I would like to start another one from within a linux container. On tty2 (Ctrl+Alt+F2) I log in, then run sudo lxc-start -n c --foreground. Then, ...
4
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0answers
405 views

Intermingled input when using local gpg-agent from remote site

I'm starting a local gpg-agent on my Mac, with the extra-socket option. Then I connect to a remote site using SSH, forwarding the remote S.gpg-agent socket to the local S.gpg-agent.extra socket. This ...
4
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0answers
706 views

slow file transfer through serial port with cat

I'm transferring a binary file to an embedded device using a custom AT command set. I'm running Lubuntu Linux on a virtual machine (Windows 7 host) and the virtual linux guest controls the physical ...
4
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0answers
1k views

How could a user log in via tty

I rented this cloud server, and it is kind of attacked recently. I can see a suspicious user logged in via tty. leetom@S152:~$ last -x ayn1 ayn1 tty1 Wed Oct 28 18:59 - ...
4
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0answers
1k views

Start application using xinit on different tty

I'm using Fedora 21, trying the following: On tty1 is running KDE, just as normal. But to speed up my games/avoid them changing something like gamma, I want to run them on a differnt tty, starting a ...
4
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0answers
1k views

How to prevent kernel or any broadcast messages from flooding the TTYs?

Because of some hot-plugging issue, similar to what talked of here, the TTY displays show a continuous stream of messages (which are also logged in the /var/log directory). Every text I key in flows ...
3
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0answers
304 views

Why do I not get a console with systemd?

I'm trying to get a login prompt on an embedded system using Debian and systemd. The system is connected via a physical serial console to a host PC. If I start the kernel with the cmdline parameters ...
3
votes
0answers
717 views

Single-user mode output to console (tty1) AND serial (ttyS0)

I am using grub2 on CentOS 7. I would like to know if it's possible to display output to both serial (ttyS0) and console (tty1) when I attempt to boot into single user mode. The ultimate goal is to ...
3
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0answers
2k views

cat: /dev/ttyS0: Input/output error

I am unable to write to or read from /dev/ttyS0 # cat /dev/ttyS0 cat: /dev/ttyS0: Input/output error the device exists, and root has permissions. # ls -lAhF /dev/ttyS0 crw------- 1 ...
3
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0answers
70 views

Detecting intervals of inactivity in the tty? (to simulate setterm --blank in fbterm)

setterm --blank n allows me to configure the virtual terminal to automatically shut the display off after n minutes of inactivity. Unfortunately, I spend all my time in fbterm, where setterm does not ...
3
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0answers
156 views

Listening on the data between a process and a serial port

I have a process that is using /dev/ttyAMA2 port to communicate with an external device on a PCB. What options do I have of listening to the communication between a process and a serial port, on an ...
3
votes
0answers
1k views

Powerline Fonts for zsh in TTY

I'm using UBUNTU 16.04. In graphical terminals like "Terminal" "guake" and "terminator" I am using zsh with Powerline-Fonts. I looked around a bit but found no proper solution to activate powerline ...
3
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0answers
326 views

What TERM types are still in common usage?

I want to support 95% of terminals on modern desktop machines (and terminal emulators on phones). Would supporting: xterm xterm-256color linux be sufficient? If not, which am I missing and where ...
3
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0answers
330 views

VConsole Setup fails: Virtual console /dev/tty0 is not in K_XLATE or K_UNICODE

Since a few days journalctl shows the following error while booting: systemd-vconsole-setup[701]: Virtual console /dev/tty0 is not in K_XLATE or K_UNICODE. After that systemd-vconsole-setup fails to ...
3
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0answers
415 views

Change TTY resolution on Fedora

I'm using Fedora 25 on ASUS laptop connected to the LG external monitor. The monitor (unlike the laptop's screen itself) doesn't show TTY full screen, while it's okay with the GUI (that's i3wm or ...
3
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0answers
232 views

Modem's GPS data is piped to wrong device

I have a SIM7100E modem running on 4.8.0-26-generic which specifies the following devices: /dev/ttyUSB1 : NMEA port for GPS NMEA data output /dev/ttyUSB2 : AT port for AT commands Connecting to ...
3
votes
0answers
493 views

Pipe audio to another user on the same computer (pulseaudio)

I am running two users at the same time because some games don't like compositing window managers, and you can't turn off compositing in Unity, my favored desktop. I don't want to run two TTYs of the ...
3
votes
0answers
231 views

Why only 4 chars get sent to serial port via command-line

I'm trying to communicate with NodeMCU (CP210x USB/UART) from command-line. However it does not respond to my commands. I have set the correct baudrate via stty 9600 raw. echo "gpio.write(0,gpio.LOW)"...
3
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0answers
951 views

Where EOF character is processed when it sent over telnet connection

Let's suppose I am connecting to telnet server, where bash is running. I am executing command cat > /tmp/qqq; typing some contents of a file and finally sending 0x0a 0x04 which meant EOF. The ...
3
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0answers
1k views

Plymouth splash not working and causing VT problems

Since I tried installing Plymouth (boot splash), I'm facing two problems : It's not working My Virtual Terminals (tt1 - 6) aren't working anymore Here what I did : Added plymouth hook (after base ...
3
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0answers
152 views

No Login on created on tty2 to 6

On my Debian Linux no Login is possible on terminals 2 to 6. Login on 1 works fine, xorg-session with XDM and awesome wm works, too. The Error Message shown on these 5 screens is: systemd-logind[...]...
2
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0answers
422 views

Can't access tty using Ctrl+Alt+F1,F2,F3 etc

Here is what I have tried: $ xev KeyRelease event, serial 43, synthetic NO, window 0x4a00001, root 0x1db, subw 0x0, time 23449801, (434,-234), root:(1305,244), state 0x1c, keycode 67 (keysym ...
2
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0answers
512 views

How to have local echo on with `screen` command?

I tried screen /dev/ttyUSB1 9600,echo but I still don't see what I type.
2
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0answers
48 views

How to prevent switching to a different tty when Xserver starts?

I am working with tty2 because Linux terminates all processes every 30 seconds and Xserver refuses to start. How can I keep tty2 in the foreground while the Xserver can go crazy in background?
2
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0answers
105 views

RS485: ioctl: ttyS1 not a tty device

I have a board with UART, and an external converter to RS485. It sits at /dev/ttyS1. The converter requires that I put the UART RTS pin to high when sending and to low when receiving. I can achieve ...
2
votes
0answers
178 views

Data loss over ttyACM* when 'cat' command is used for data transfer

I have a development board which will have 3 ACM interfaces when connected to Ubuntu host and i want to transfer data from Host to Device over ttyACM3. I have followed the following procedure for ...
2
votes
0answers
128 views

Opening character device for reading in parallel by multiple processes on Linux

I would like to open a character device e.g. /dev/tty1 by multiple processes in a way that would not interfere reads between them. I noticed that if one process consumes a byte, no other process would ...
2
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0answers
165 views

Sending a script to tty instead of vt (specific problem stated, other solutions welcome)

I am curious as to what is the simplest way of sending an executed command (in this case, a bash script), that had been executed in a terminal emulator into a tty. Context: I am sick and tired of the ...
2
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0answers
626 views

Configuring serial driver sc16is7xx

Initial Question I work with the NXP chip SC16IS740 as a peripheral to an embedded linux system (mainline kernel v4.8). The usecase is quite simple, a continuosly transmitting uart line (9600 8n1) ...
2
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0answers
84 views

How to control mysql with zpty?

I try to write a wrapper script for the mysql console client. While working on this, I stumbled upon zpty. It seems perfect. My first goal was to retrieve some table contents, but I already fail ...
2
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0answers
497 views

Audit and or monitor every command sent through an SSH connection?

I am writing because I need a way to monitor what my users send via ssh. I have a jumphost and I tried the following: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/...
2
votes
0answers
49 views

Splitting a laptop into 2 consoles

I have Ubuntu 16.04 on my laptop, Dell Latitude E4200. It sometimes lands in a docking station with a set of peripheral devices: screen keyboard mouse sometimes some USB drives, etc (as an aside) ...
2
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0answers
940 views

How to send AT commands to serial interface in Yocto Linux?

I have a XBee device attached to the ttyMDF1 interface on an Intel Edison board running Yocto linux. I need to configure the XBee by sending AT commands to it. I have tried to open a getty /dev/...
2
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0answers
381 views

Verizon LG VL600 USB 4G Modem

I am trying to connect an LG VL600 USB 4G Modem from Verizon on a Debian based machine (tried on Linux Mint and Raspberry Pi). I got it working on Windows 7 Virtualbox VM, so I know the device and ...
2
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0answers
66 views

'Unbusy' terminals which will be logged out when TMOUT is reached

I would like auto-logout some terminal sessions with a TMOUT (timeout) configuration, but in that case the users leave a program opened for which the 'unbusy' sign is the ZERO I/O between server and ...
2
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0answers
3k views

cat /dev/ttyS0 Input/output error

I created infrared receiver as in LIRC manual (http://www.lirc.org/receivers.html). And tested it on windows using program called Terminal. When I switched on RTS pin DCD pin was also switched on ...
2
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0answers
211 views

How to use secondary VGA device for TTYs

I have a machine (a virtual XEN DomU, but I don't think it matters) with two video cards. I would like to display the TTYs on the monitor connected to the secondary video card (i.e., not the display ...
2
votes
0answers
856 views

Can't login using serial on ttyO0 - BeagleBone Black

I boot Beaglebone Black, connected to my desktop by serial. It was working great, until now. Beagle is booting, output shows up on the console, but at the end I can't log in. I can't type the login, ...
2
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0answers
343 views

How do I assign the controlling terminal to other process?

I use TIOCSCTTY to forcibly take over the controlling terminal in other "remote" application. But after the application finishes running, controlling terminal gets orphaned and bash stops reacting to ...
2
votes
0answers
932 views

tty blinking cursor not at insertion point

I have an Ubuntu 12.04 system where I, at reboot, login a root. This morning I did the things I had to and thought about running apt-get -y upgrade I started typing this but before pressing Enter I ...
2
votes
0answers
168 views

Controlling ppp's chat buffering

I looked at the ppp chat source and it uses putchar to write to the device. When PPP is run over a line discipline like n_gsm, which multiplexes a tty via the GSM 07.10 protocol, a lot of extra data ...
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0answers
31 views

What does it mean for the X server to live on a particular tty?

On Linux, how does the X server establish a relationship with a particular tty (such as tty7) so that the X server can receive input and draw on the screen only when that tty is in the foreground? How ...
1
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0answers
74 views

Run GUI Application in a TTY Without Window Manager

What commands and variables need to be set up so I can run a GUI app on one the of the ttys without the Window Manager? Special Note: This question has been edited due to comments for testing and now ...
1
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0answers
30 views

Logged out when switching tty

I ugraded my Debian from Stretch to Buster. Now each time I switch the tty (by Ctrl-Alt-FX) from my graphical instance (F7) to something else (e.g. F1) and back, I have to login again. It seems that ...
1
vote
0answers
45 views

Problem with USB Driver VID and PID

I'm trying get data from an USB to my application. My device is a Power Frequency Inverter that have a Type B USB as output, in the another side have an USB type A plugged in the my computer. When I ...
1
vote
0answers
139 views

Listen in to data read from file descriptor to ttyS

I have a serial device under /dev/ttyS0 and an application that is reading from the serial device (but not writing to it). I wanted to listen in to the data that is coming in on the serial device but ...
1
vote
0answers
24 views

Reduce used display size for both X server and console

I have the situation that I have a LCD display that I would like to use but I want to have a "black unused frame" around the displayed content. Is there a kernel setting which controls the used ...
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0answers
245 views

PTY allocation request failed on channel 0

My remote vm server's password has expired, i cann't change password. [user@localhost ~]$ ssh root@x.x.x.x root@x.x.x.x's password: PTY allocation request failed on channel 0 WARNING: Your password ...