The goal is to get modbus ascii working with a Wallbox from ABL. So I placed a RS485 to TCP converter in the box, created a pseudo tty for my application and got the wrong frame. The answer starts with > and should start with :. So my approach is the following:

Terminal1: sudo socat -d -d -d pty,link=/dev/ttyVA00,echo=0,perm=0777 pty,link=/dev/ttyVB00,echo=0,perm=0777

Terminal2: sudo socat -d -d -d pty,link=/dev/ttyV0,perm=0777 tcp:10.10.49.249:502

Terminal3: cat /dev/ttyVB00 > /dev/ttyV0

Terminal4: cat /:/g' > /dev/ttyVB00
           
Terminal5: ./modpoll -m ascii /dev/ttyVA00 -b 38400 -d 8 -p even -t4 -c 2 -0

And this works! Could you give advice on how to simplify the socat solution and how to get it to autostart?

### Context To restore the standard input, standard output and/or standard error (file descriptors 0, 1 and/or 2 respectively) of a process to the keyboard and/or display of an interactive shell (bash) session, I have seen here that one can execute either of the following: $ exec &>/dev/tty or $ exec &>$(tty) Whereas $(tty) (a command substitution) returns /dev/pts/X where X is the number associated to the currently active terminal window (pseudo-tty), thereby explicitly pointing the redirection to the "real" filename associated with the terminal in which the command is entered, in contrast /dev/tty is a character file which *seems* to appear identical to different processes (i.e. to different concurrent terminal windows). In man 4 tty it says: > The file /dev/tty [...] is a synonym for the controlling terminal of a process... In The Open Group Base Specifications Issue 8, Chapter 10 it says: > **/dev/tty** > > In each process, a synonym for the controlling terminal associated with the process group of that process, if any. It is useful for programs or shell procedures that wish to be sure of writing messages to or reading data from the terminal no matter how output has been redirected. It can also be used for applications that demand the name of a file for output, when typed output is desired and it is tiresome to find out what terminal is currently in use. ### Question Since /dev/tty is a file and not a symbolic link like /dev/fd or /proc/self, how can it "point" to different terminal processes when interpreted in different terminal windows? What does it mean in Unix/Linux parlance to be "a synonym" when not a symbolic link or a hard link — I mean: what is interpreting such a "synonym" when invoked on a command line and how?

I use arduino ide on arch linux with arduino uno connected via USB. I am sure that I choosed right port and board in ide menu. when I run ls -l /dev/ttyACM* I get:

crw-rw---- 1 root uucp 166, 0 14. dub 12.44 /dev/ttyACM0
crw-rw-rw- 1 root uucp 166, 1 14. dub 12.54 /dev/ttyACM1

but when I click upload I get this error:

Sketch uses 440 bytes (1%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.

avrdude: Version 6.3, compiled on Jul  7 2020 at 19:38:43
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/ 
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "//etc/avrdude.conf"
         User configuration file is "/home/john/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/ttyACM1
         Using Programmer              : arduino
         Overriding Baud Rate          : 115200
avrdude: ser_open(): can't open device "/dev/ttyACM1": Input/output error

avrdude done.  Thank you.

the selected serial port 
 does not exist or your board is not connected

Error remains on newest linux kernel and LTS. --- My device is Lenovo thinkpad X390: Linux 5.11.14-arch1-1 --- When I plug arduino to usb and then run sudo dmesg I get this messages:

[ 1605.378324] usb 1-4: new full-speed USB device number 14 using xhci_hcd
[ 1605.520509] usb 1-4: New USB device found, idVendor=2341, idProduct=0043, bcdDevice= 0.01
[ 1605.520517] usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=220
[ 1605.520521] usb 1-4: Manufacturer: Arduino (www.arduino.cc)
[ 1605.520523] usb 1-4: SerialNumber: 7583434383935150E152
[ 1605.523881] cdc_acm 1-4:1.0: ttyACM1: USB ACM device
[ 1630.618749] usb 1-9: reset full-speed USB device number 10 using xhci_hcd
[ 1630.792727] audit: type=1130 audit(1618567069.016:82): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=fprintd comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 1632.601215] audit: type=1100 audit(1618567070.822:83): pid=29714 uid=1000 auid=1000 ses=1 msg='op=PAM:authentication grantors=? acct="john" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=failed'
[ 1635.720577] audit: type=1100 audit(1618567073.942:84): pid=29714 uid=1000 auid=1000 ses=1 msg='op=PAM:authentication grantors=pam_faillock,pam_permit,pam_faillock acct="john" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=success'
[ 1635.721507] audit: type=1101 audit(1618567073.942:85): pid=29714 uid=1000 auid=1000 ses=1 msg='op=PAM:accounting grantors=pam_unix,pam_permit,pam_time acct="john" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=success'
[ 1635.722751] audit: type=1110 audit(1618567073.946:86): pid=29714 uid=1000 auid=1000 ses=1 msg='op=PAM:setcred grantors=pam_faillock,pam_permit,pam_faillock acct="root" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=success'
[ 1635.727018] audit: type=1105 audit(1618567073.949:87): pid=29714 uid=1000 auid=1000 ses=1 msg='op=PAM:session_open grantors=pam_limits,pam_unix,pam_permit acct="root" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=success'

--- How can I fix this ? Thank you for help **PS:** If you need any more information, comment below and I will add it soon as possible.

System info: macOS Sierra 10.12.6 zsh 5.4.2 (x86_64-apple-darwin16.7.0) GNU bash, version 4.4.12(1)-release (x86_64-apple-darwin16.3.0) Scroll to the **EXAMPLES** at the bottom if you just want to dig in to the simplified examples that I made. NOTE: I am not a big zsh user. --- I was looking at the [fzf](https://github.com/junegunn/fzf) keybindings for [bash](https://github.com/junegunn/fzf/blob/master/shell/key-bindings.bash#L59) and [zsh](https://github.com/junegunn/fzf/blob/master/shell/key-bindings.zsh#L73) . Notice how they both run a variable command $(__fzfcmd). __fzfcmd by default outputs fzf to stdout and the parameter substitution just runs command (fzf) resulting from the output. One difference between the bash and zsh script is that the bash one further pipes the output of $(__fzfcmd) but zsh just captures it inside an array. My guess is because of a problem in zsh when you further pipe the output of fzf where you can't input to fzf and the process piped to by fzf doesn't get any stdin. Your only choice is to ^Z or ^C. ^C seems to background the process for some reason. Or maybe they just wanted it in an array so they could could [run zle vi-fetch-history on it](https://github.com/junegunn/fzf/blob/master/shell/key-bindings.zsh#L78) . The bash version does some magic in the key binding with ["\e^": history-expand-line](https://github.com/junegunn/fzf/blob/master/shell/key-bindings.bash#L83) Now fzf isn't important. It seems like you just need a program that outputs to the tty to be called by parameter substitution to cause this problem. So I will show some simpler examples. Here are some other commands that output to the tty that can cause this problem in zsh: - [vipe](https://linux.die.net/man/1/vipe) (run editor in middle of a pipe) - 'vim -' (make vim read from stdin. similar to vipe but won't output to stdout) --- In the examples below, replace every occurrence of vipe with vim - if you don't want to do a separate install. Just remember that vim - won't output the editor contents to stdout like vipe does. **EXAMPLES:** 1) echo 1 | vipe | cat # works in both bash and zsh 2) echo 1 | $(echo vipe) | cat # works in bash only. zsh problem with no output until I hit ^C: ^C zsh: done echo 1 | zsh: suspended (tty output) $(echo vipe) | zsh: interrupt cat # seems like the process is backgrounded. I can still see it in jobs command 3) cat >(cat) # works in both bash and zsh # The following don't have and input pipe to vipe. # Type something then send EOF with ^D 6) vipe | cat # works for both 7) $(echo vipe) | cat # works for both Now, I'm mostly wondering why 2) has a problem for zsh but not for bash and why 4) and 5) fixes the problem for zsh. The requirements for zsh to have this problem to seem to be exactly what I put in the title: - input pipe - command run by variable/parameter substitution that has tty output - output pipe **UPDATE** I added another workaround that doesn't cause zsh to have this problem, 5). It's similar to 4) but instead of redirecting stdout directly into stin, I redirect it into a file that redirects into stdin using process substitution.

So, I did a certification lab lately and after I logged in my ssh, I cannot use a command longer than X line (4 in F server lab and 29 in C server lab. My host kali machine is working and I've tried several thing including: - 'stty sane; bash' - '/bin/sh' - 'reset' - changing the terminal from qterminal to gnome-terminal - use tmux - restarting / rebooting the lab and my host - I've tried seq 1 100 output in ssh and exit (worked) but I cannot do it if I have interactive session in the ssh - of course I can use seq 1 100 in my host machine That's all that I've tried, are there any other data that I should provide in my host machine? I cannot provide .profile and .bashrc of the server machine because I cannot do stdout that much of line and I also cannot transfer it (I really don't understand why). In the same time, I've asked the support lab team, hoping that they answer me in no time. Any Idea or approach that I should try on?

I want to get virtual machine in a TTY (VT*) in fullscreen like GDM3 can take a TTY (VT*) for the graphic part of linux I want DISPLAY (heard as the output of a graphic server, here the VMs) to be redirected in a TTY (VT*), and not in a window like usually It will make like the computer run multiple OS at the same time but in fact it's a Linux Kernel who virtualize the differents OS that we can see on the different TTY (VT*) You know, the TTY (VT*) in CTRL + ALT + Fi ---------- Okay ---------- Not okay

I have set up a runit service to autologin in /dev/tty16 and the shell profile executes dbus-run-session Hyprland, however, I noticed that Hyprland, or GUIs start on the 'active' or the currently shown tty. How can I specify what tty to use a GUI application in?

I'm confused from the actual meaning of the echoing feature implemented in Linux TTY driver. As far as I know, a pseudo-terminal pair (PTY pair) consists of a PTY master, a PTY slave and a line discipline all implemented in kernel code (i.e. kernel code running in kernel space). From my understanding, echoing is the feature of sending back what is written on the master side ptm so that the process opening such a fd (by opening the PTY multiplexer /dev/ptmx device file) receives back what it has written to. My questions: - is this echo feature implemented within the line discipline kernel code ? - does this echo feature apply only to the PTY master side, i.e. it doesn't send back what is written to the PTY slave side /dev/pts/x ? Thanks.

Essentially, I noticed I am unable to write to my user who is using gnome-terminal. tty returns /dev/pts/1, but I am unable to write there as root. Instead, it returns as follows:

myuser@pegasus:/$ tty
/dev/pts/1
root@pegasus:/# write myuser pts/1
write: myuser is not logged in on pts/1

I have also tried write myuser tty2, and tried not specifying the terminal, but nothing happens. How can I write to my session? The inverse works fine:

myuser@pegasus:/$ write root pts/0
hi!
please respond
root@pegasus:/# 
Message from myuser@pegasus on pts/1 at 22:05 ...
hi!
please respond
EOF

Here is what the logins look like.

root@pegasus:/# who -aT
           system boot  2025-06-19 21:34
           run-level 5  2025-06-19 21:34
myuser ? seat0        2025-06-19 21:34   ?          2982 (login screen)
myuser + tty2         2025-06-19 21:34 00:37        2982 (tty2)
           pts/1        2025-06-19 21:41             25698 id=ts/1  term=0 exit=0

myuser@pegasus:/$ loginctl
SESSION  UID USER      SEAT  LEADER CLASS         TTY   IDLE SINCE
     11    0 root      -     79869  manager-early -     no   -    
      2 1000 myuser seat0 2891   user          tty2  no   -    
      3 1000 myuser -     2911   manager       -     no   -    
    c11    0 root      -     79732  user-early    pts/0 no   -    

4 sessions listed.

I'm trying to get console output on **both the onboard iGPU (Intel i915, HDMI output)** and **the AST BMC (IPMI remote display)** on my headless server setup. #### Hardware and OS * **Motherboard**: ASUS Pro WS W680-ACE IPMI * **CPU**: Intel i9-14900 * **OS**: Ubuntu 24.04.2 LTS (Pro), kernel 6.8.0-60-generic, UEFI boot * systemd is in use and default GRUB is installed #### BIOS Settings All relevant GPU-related options are enabled:

Primary Display       [CPU Graphics]
iGPU Multi-Monitor    [Enabled]
DVMT Pre-Allocated    [64M]
RC6 (Render Standby)  [Enabled]

When I boot into the BIOS firmware setup, **both HDMI and IPMI outputs mirror the BIOS screen correctly**, confirming that hardware-level multi-display support is working. #### Framebuffer Devices After booting Linux:

$ ls /dev/fb*
/dev/fb0  /dev/fb1

$ cat /sys/class/graphics/fb*/name
i915drmfb
astdrmfb

So: * /dev/fb0 = Intel iGPU (HDMI) * /dev/fb1 = AST BMC (IPMI) #### What I’ve Tried I’ve tried modifying /etc/default/grub with various combinations of fbcon=map: and console=ttyX: 1. GRUB_CMDLINE_LINUX_DEFAULT="fbcon=map:1,0 console=tty1 console=tty2" → **Only IPMI (fb1) works**, HDMI stays black. 2. GRUB_CMDLINE_LINUX_DEFAULT="fbcon=map:0,1 console=tty1 console=tty2" → **Only HDMI (fb0) works**, IPMI stays black. 3. GRUB_CMDLINE_LINUX_DEFAULT="fbcon=map:both console=tty1 console=tty2" → **Nothing appears on either display**. (Yes, I realize fbcon=map:1,0 maps tty1 to fb1 and tty2 to fb0 — that behavior is expected.) I also enabled getty@tty2.service and confirmed it’s running. --- ### What I Want * Ideally: **Same console output mirrored** on both HDMI and IPMI * Acceptable: **Separate virtual terminals** (e.g., tty1 on IPMI, tty2 on HDMI) But so far I can only get one to work at a time, depending on how I order fbcon=map. Any suggestions? Is this a limitation in fbcon, the kernel, or something I can work around with udev, early KMS, or a boot service?

### Problem Consider a command like this: binary_output 2>error.log where tool is arbitrary and ssh is a wrapper or some ssh-like-contraption that allows the above to work. With regular ssh it doesn't work. I used sudo here but it's just an *example* of a command that requires tty. I'd like a general solution, not specific to sudo. --- ### Research: the cause With regular ssh it doesn't work because: - sudo needs tty to ask for password (or to work at all ), so I need ssh -t ; actually in this case I need ssh -tt. - On the other hand ssh -tt will make sudo read the password from binary_input. I want to provide the password via my local tty. Even if sudo is configured to work without password or if I inject the password to the binary_input, ssh -tt will make sudo and tool read from the remote tty and write output *and* errors and prompts to the remote tty. Not only I won't be able to tell the output and the errors/prompts apart locally. All the streams will be processed by the remote tty and this will mangle data (you can see this in some examples in this answer of mine , in the section entitled "Some practice"). --- ### Research: comparison to commands that work - This local command is the reference point. Let's assume it successfully processes some binary data: binary_output - If I need to run tool on a server, I can do this. Even if ssh asks for my password , this will work: binary_output In this case ssh is transparent for binary data. - Similarly local sudo can be transparent. The following command won't mangle the data even if sudo asks for my password: binary_output - But running tool on the server with sudo is troublesome: binary_output In this configuration ssh and sudo *together* cannot be transparent in general. Finding a way to make them transparent is the gist of this question. --- ### Research: similar questions I have found few similar questions: - Use sudo with ssh command and capturing stdout This question cares about stdout only. The existing answer (from the author of the question) advises sudo -S which consumes stdin. I don't really want to alter my binary_input. And I would appreciate a solution not specific to sudo. - stderr over ssh -t This concentrates on passing Ctrl+c and the background is GNU parallel. A workaround that only makes Ctrl+c work without a remote tty is not enough for me. - SSH: Provide additional “pipe” fds in addition to stdin, stdout, stderr This is a good start (especially this answer , I think). However here I want to emphasize the need for tty. I want a solution that automates things and allows me to use remote sudo (or whatever) as if it was local. --- ### My explicit question In the following command: binary_output 2>error.log requires-tty is a placeholder for code that requires a tty but processes binary data from its stdin to its stdout. It seems I need ssh -tt, otherwise requires-tty will not work; and at the same time I mustn't use ssh -tt, otherwise the binary data will be mangled. How can I solve this problem in a convenient way? requires-tty can be sudo … but I don't want a solution specific to sudo. I imagine the ideal(?) solution will be a script/tool that replaces ssh in the above invocation and just works. It should(?) connect the remote stdin, stdout and stderr each to its local counterpart, *and* the remote tty to the local tty. If it's possible, I prefer a client-side solution that does not require any server-side companion program.

I have this makefile:

all: 
        sudo watch "ls -l" > /dev/null &
        @echo line 1
        @echo line 2
        @echo line 3
        @echo line 4

Running watch (**or any other process that somehow changes the terminal**) ruins the terminal. This is the output. You can see these big spaces. Also, I can't see the characters afterwards, when I write:

me@me:/tmp$ make
watch "ls -l" > /dev/null &
line 1
line 2
      line 3
            line 4
                  me@me:/tmp$

Is there a way to prevent a process changing the terminal? **A clarification**: watch is just a **reproductible example**. I'm using another app that should run as daemon, but still ruins the terminal. --- Edit: I start this app (on this example, the app is watch) with sudo **A workaround** is to start it without sudo - then the terminal isn't ruined. The disadvantage in that is, that I need to chown this process to not be root:root.

I'm working on a minecraft server with OS Ubuntu server 20.04 So far they haven't given me any problems (it's fantastic!), I know some things about linux (some don't exaggerate) Until something came to me. I'll be out of the house, but I'll have my laptop. The problem is the following, I want to play minecraft with my friends but every time I start the computer it asks me to enter the password. Things I'd like to do: Enable Auto-login What I've already tried: systemctl edit getty@tty1.service [Service] ExecStart= ExecStart=-/usr/bin/agetty --autologin simao --noclear %I 38400 linux I've also tried replacing the last line with ExecStart=-/usr/bin/agetty --autologin simao --noclear %I %TERM What happens when turning off and on again: On tty1 appears the normal starting and then only a flashing _ When running the following command sudo systemctl --failed Gives the following output UNIT LOAD ACTIVE SUB DESCRIPTION getty@tty1.service loaded failed failed Getty on tty1 Then I ran the following command sudo systemctl status getty@tty1.service And gives the following output " getty@tty1.service - Getty on tty1 Loaded: loaded (/lib/systemd/system/getty@.service; enabled; vendor preset: enabled) Drop-In: /etc/systemd/system/getty@tty1.service.d └─override.conf Active: failed (Result: start-limit-hit) since Mon 2022-07-25 12:39:35 UTC; 11min ago Docs: man:agetty(8) man:systemd-getty-generator(8) http://0pointer.de/blog/projects/serial-console.html Process: 1077 ExecStart=/usr/bin/agetty --autologin simao --noclear tty1 38400 linux (code=exited, status=0/SUCCESS) Main PID: 1077 (code=exited, status=0/SUCCESS) Jul 25 12:39:35 minecraft-server-simao-vilas systemd: getty@tty1.service: Succeeded. Jul 25 12:39:35 minecraft-server-simao-vilas systemd: getty@tty1.service: Scheduled restart job, restart counter is at 5. Jul 25 12:39:35 minecraft-server-simao-vilas systemd: Stopped Getty on tty1. Jul 25 12:39:35 minecraft-server-simao-vilas systemd: getty@tty1.service: Start request repeated too quickly. Jul 25 12:39:35 minecraft-server-simao-vilas systemd: getty@tty1.service: Failed with result 'start-limit-hit'. Jul 25 12:39:35 minecraft-server-simao-vilas systemd: Failed to start Getty on tty1. EDIT: If someone needs more info, only ask and i will edit the post with the info right away (not exactly but the fast i can)

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 root root 4, 64 Nov 18 12:09 /dev/ttyS0 # setserial -g /dev/ttyS0 /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4 # dmesg | egrep -i 'serial|ttys' [ 1.243271] Serial: 8250/16550 driver, 1 ports, IRQ sharing disabled [ 2703.151301] ttyS0: LSR safety check engaged! # cat /proc/devices | grep tty 4 tty 4 ttyS 5 /dev/tty I have serial enabled in my kernel: # grep SERIAL config CONFIG_SERIAL_8250=y CONFIG_SERIAL_8250_NR_UARTS=1 CONFIG_SERIAL_8250_RUNTIME_UARTS=1 CONFIG_SERIAL_CORE=y **What do I have to do to make serial work ?**

Can I, through a trick or a module, make the Micro editor behave in a separate TTY as if I had started it directly from a console/terminal emulator in my desktop environment? - micro | a modern and intuitive terminal-based text editor **Setup**: Debian 12, Bash, KDE/Gnome ##### The core feature I'm searching for: I just want to mark text/ part of a text using the arrow keys + Shift. Is this possible, or is it fundamentally impossible because the Linux kernel console (e.g., tty1) does not support this? ##### Results I discovered: >The kernel console (TTY) does not support extended modifier sequences like Shift+arrow keys, which means it is not possible to select text using Shift+arrow keys in the Micro editor when running in the TTY. > >According to the official man page console_codes(4), the Linux console implements only a subset of the VT102 and ECMA-48/ISO 6429/ANSI X3.64 terminal controls. > >In particular, it lacks support for extended input sequences that are handled by modern terminal emulators like xterm. This means the console does not send escape sequences for combined keys such as Shift+arrow keys. - linux man page for console_codes - console_codes - Linux console escape and control sequences - bash: Shift+arrow keys make A,B,C,D - console_codes(4) — Linux manual page The loadkeys keymaps use tricks to assign different sequences to function keys (F1–F12) combined with modifiers like Alt or Ctrl. But that probably works because the kernel has explicit support for it but it looks like not for Shift+Arrow. - keymaps (5) From @Gilles 'SO- stop being evil' answer: - Detecting shift + keyup/down in the terminal >Terminals don't send key up events. (Your use case doesn't require them, though, according to your description.) > >Unless you can afford to require a specific terminal emulator (e.g. recent-ish xterm), don't rely on the user being able to type Shift+Up. Support an alternate method, such as a “start multiple selection” key followed by plain Up/Down

We would like to run some curses based apps in background. These apps use curses and get the current tty port name to be used internally to map log files and others context-terminal associations. In some tests just redirecting the input from curses apps that don't read the keyboard to a known pts, worked. And so they can be executed in background, since I reserve a tty (or pseudo tty) for that. Is it possible to mock a tty, or has a reserved pts to some automatic running purposes, like that? We plain to launch them through crontab.

I have a binary file(obtained from assembly code). I need to transfer this file to an fpga serially via ttyUSB0. I read in some posts that using cat and echo data can be transferred to ttyS0.

echo -ne '\033[2J' > /dev/ttyS1  
cat  < /dev/ttyS1

Does this apply for ttyUSB0 as well? If not, please suggest me other ways to transfer binary file via ttyUSB0.

I login from the tty. my .xinit file had the command exec i3I got tired of constantly retyping startx after login so i put exec startxat the end of my .bash_profile. now every time I type my login credentials it flashes a failed startx the reprompts me for the login credentials again. I can't log into the computer anymore. I tried pressing ctrl-c which didn't do anything and I tried holding the power button which just turned off the laptop. edit: I use the newest version of Linux mint cinnamon which comes with light DM display manager by default. I had only disabled it for a day which was when the issue happened

> Remove kms from the HOOKS array in /etc/mkinitcpio.conf and [regenerate the initramfs](https://wiki.archlinux.org/title/Regenerate_the_initramfs) . This will prevent the initramfs from containing the nouveau module making sure the kernel cannot load it during early boot. The [nvidia-utils](https://archlinux.org/packages/?name=nvidia-utils) package contains a file which blacklists the nouveau module once you reboot. The above quote from the Arch Linux wiki page for [NVIDIA](https://wiki.archlinux.org/title/NVIDIA) says to remove the kms hook after installing nvidia drivers so that nouveau can't conflict with them (or at least I think that's what it means!). However upon removing it, I experience problems with my vconsole tty on boot, including the font not being set correctly and the login prompt being (visually) corrupted by a kernel error msg:

[[bottom 20% of an ascii art defined in /etc/issue that had displayed fully when kms wasn't deleted]]
emmy login: [    5.559980] i915 0000:00:02.0: [drm] *ERROR* Failed to probe lspcon

Then I saw that even with the kms hook added lsmod | grep nouveau shows nouveau isn't loaded. So what's the point of removing the kms hook when it seems that all it does is cause errors from weird loading orders of modules? And what does the hook actually do? Here is my journalctl for both cases (I am using a intel i915 integrated graphics card + an nvidia GTX 1650 card): KMS removed: journalctl -b | grep -E "nvidia|drm|fbcon|i915"

May 04 23:39:11 emmy kernel: Command line: initrd=\intel-ucode.img initrd=\initramfs-linux.img root=UUID=c0f85f88-6e8a-4002-8367-52c4141be5c6 rw nvidia_drm.modeset=1
May 04 23:39:11 emmy kernel: The simpledrm driver will not be probed
May 04 23:39:11 emmy kernel: Kernel command line: initrd=\intel-ucode.img initrd=\initramfs-linux.img root=UUID=c0f85f88-6e8a-4002-8367-52c4141be5c6 rw nvidia_drm.modeset=1
May 04 23:39:11 emmy kernel: ACPI: bus type drm_connector registered
May 04 23:39:11 emmy kernel: fbcon: Deferring console take-over
May 04 23:39:11 emmy kernel: fbcon: Taking over console
May 04 23:39:11 emmy systemd: Starting Load Kernel Module drm...
May 04 23:39:11 emmy systemd: modprobe@drm.service: Deactivated successfully.
May 04 23:39:11 emmy systemd: Finished Load Kernel Module drm.
May 04 23:39:11 emmy kernel: nvidia: loading out-of-tree module taints kernel.
May 04 23:39:11 emmy kernel: nvidia: module verification failed: signature and/or required key missing - tainting kernel
May 04 23:39:11 emmy kernel: nvidia-nvlink: Nvlink Core is being initialized, major device number 238
May 04 23:39:11 emmy kernel: nvidia 0000:01:00.0: enabling device (0000 -> 0003)
May 04 23:39:11 emmy systemd-modules-load: Inserted module 'nvidia_uvm'
May 04 23:39:12 emmy kernel: nvidia-modeset: Loading NVIDIA UNIX Open Kernel Mode Setting Driver for x86_64  570.144  Release Build  (archlinux-builder@echo archlinux)
May 04 23:39:12 emmy kernel: [drm] [nvidia-drm] [GPU ID 0x00000100] Loading driver
May 04 23:39:13 emmy kernel: i915 0000:00:02.0: [drm] Found coffeelake (device ID 3e9b) integrated display version 9.00 stepping N/A
May 04 23:39:15 emmy kernel: i915 0000:00:02.0: vgaarb: deactivate vga console
May 04 23:39:15 emmy kernel: i915 0000:00:02.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=io+mem:owns=io+mem
May 04 23:39:15 emmy kernel: i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/kbl_dmc_ver1_04.bin (v1.4)
May 04 23:39:15 emmy kernel: mei_hdcp 0000:00:16.0-b638ab7e-94e2-4ea2-a552-d1c54b627f04: bound 0000:00:02.0 (ops i915_hdcp_ops [i915])
May 04 23:39:15 emmy kernel: [drm] Initialized nvidia-drm 0.0.0 for 0000:01:00.0 on minor 0
May 04 23:39:15 emmy kernel: nvidia 0000:01:00.0: [drm] No compatible format found
May 04 23:39:15 emmy kernel: nvidia 0000:01:00.0: [drm] Cannot find any crtc or sizes
May 04 23:39:15 emmy kernel: i915 0000:00:02.0: [drm] *ERROR* Failed to probe lspcon
May 04 23:39:15 emmy kernel: [drm] Initialized i915 1.6.0 for 0000:00:02.0 on minor 1
May 04 23:39:15 emmy kernel: fbcon: i915drmfb (fb0) is primary device
May 04 23:39:15 emmy kernel: snd_hda_intel 0000:00:1f.3: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
May 04 23:39:15 emmy kernel: i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device

KMS not removed (login screen and ascii art works fine):

May 04 23:47:03 emmy kernel: Command line: initrd=\intel-ucode.img initrd=\initramfs-linux.img root=UUID=c0f85f88-6e8a-4002-8367-52c4141be5c6 rw nvidia_drm.modeset=1
May 04 23:47:03 emmy kernel: The simpledrm driver will not be probed
May 04 23:47:03 emmy kernel: Kernel command line: initrd=\intel-ucode.img initrd=\initramfs-linux.img root=UUID=c0f85f88-6e8a-4002-8367-52c4141be5c6 rw nvidia_drm.modeset=1
May 04 23:47:04 emmy kernel: ACPI: bus type drm_connector registered
May 04 23:47:04 emmy kernel: fbcon: Deferring console take-over
May 04 23:47:04 emmy kernel: fbcon: Taking over console
May 04 23:47:04 emmy kernel: i915 0000:00:02.0: [drm] Found coffeelake (device ID 3e9b) integrated display version 9.00 stepping N/A
May 04 23:47:04 emmy kernel: i915 0000:00:02.0: vgaarb: deactivate vga console
May 04 23:47:04 emmy kernel: i915 0000:00:02.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=io+mem:owns=io+mem
May 04 23:47:04 emmy kernel: i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/kbl_dmc_ver1_04.bin (v1.4)
May 04 23:47:04 emmy kernel: i915 0000:00:02.0: [drm] *ERROR* Failed to probe lspcon
May 04 23:47:04 emmy kernel: [drm] Initialized i915 1.6.0 for 0000:00:02.0 on minor 0
May 04 23:47:04 emmy kernel: fbcon: i915drmfb (fb0) is primary device
May 04 23:47:04 emmy kernel: i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device
May 04 23:47:04 emmy systemd: Starting Load Kernel Module drm...
May 04 23:47:04 emmy systemd: modprobe@drm.service: Deactivated successfully.
May 04 23:47:04 emmy systemd: Finished Load Kernel Module drm.
May 04 23:47:04 emmy kernel: nvidia: loading out-of-tree module taints kernel.
May 04 23:47:04 emmy kernel: nvidia: module verification failed: signature and/or required key missing - tainting kernel
May 04 23:47:04 emmy kernel: nvidia-nvlink: Nvlink Core is being initialized, major device number 236
May 04 23:47:04 emmy kernel: nvidia 0000:01:00.0: enabling device (0000 -> 0003)
May 04 23:47:04 emmy systemd-modules-load: Inserted module 'nvidia_uvm'
May 04 23:47:04 emmy kernel: nvidia-modeset: Loading NVIDIA UNIX Open Kernel Mode Setting Driver for x86_64  570.144  Release Build  (archlinux-builder@echo archlinux)
May 04 23:47:04 emmy kernel: mei_hdcp 0000:00:16.0-b638ab7e-94e2-4ea2-a552-d1c54b627f04: bound 0000:00:02.0 (ops i915_hdcp_ops [i915])
May 04 23:47:04 emmy kernel: [drm] [nvidia-drm] [GPU ID 0x00000100] Loading driver
May 04 23:47:05 emmy kernel: snd_hda_intel 0000:00:1f.3: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
May 04 23:47:06 emmy kernel: [drm] Initialized nvidia-drm 0.0.0 for 0000:01:00.0 on minor 1
May 04 23:47:06 emmy kernel: nvidia 0000:01:00.0: [drm] No compatible format found
May 04 23:47:06 emmy kernel: nvidia 0000:01:00.0: [drm] Cannot find any crtc or sizes

I don't see what the difference is because both end up with my i915 card using the framebuffer.

I have a command (systemctl status) that halts and waits for keystrokes if I run it in a terminal that is not tall enough. I'm not interested in this behavior and can't find an option to bypass it. If I make the output of the command not a tty, it doesn't stop. So what is the most efficient way to do so? So far I am using

systemctl status | tee /dev/null

but are there shorter or more efficient options? Although I ask the question for systemctl (that has a direct way to handle this), I'm curious to know the answer(s) for the more general case where a command has different tty and non-tty behaviors, and I want the non-tty behavior on a tty. (Ubuntu 24.04 and bash 5.2.21)