All Questions(ubuntu)

It is to my understanding that in /bin we have some binary executables that are just compiled C programs. Out of curiosity, I decided to play with them and I opened ls with sudo privileges using nano, and added the character 0 at the beginning. I saved the file and, to my amusement, I checked that indeed, executing the ls command in a terminal does not work.

What I did not expect is that after deleting this character I had added, the ls command still does not work and segfaults.

If the files contained in /bin are nothing but machine code with ones and zeros, why does deleting a character that we have previously added not yield a program that works?

gnuplot> set xlabel "{/Symbol t}"
gnuplot> set term png; set out "test.png"; plot x;set out

Terminal type is now 'png'
Options are 'truecolor nocrop enhanced butt size 640,480 font "arial,12.0" '
gdImageStringFT: fontconfig: Didn't find expected font family. Perhaps URW Type 1 fonts need installing? while printing string t with font Symbol
gdImageStringFT: fontconfig: Didn't find expected font family. Perhaps URW Type 1 fonts need installing? while printing string t with font Symbol

The xlabel is blank

Similar error message for the jpeg and gif terminals. The PDF terminal works fine, and τ is printed fine.

packages installed: gnuplot-qt/noble,now 6.0.0+dfsg1-1ubuntu3 amd64 fonts-urw-base35/noble,noble,now 20200910-8 all

gnuplot 6.0 patchlevel 0 OS: Ubuntu 24.04.1 LTS x86_64 Kernel: 6.8.0-47-generic DE: GNOME 46.0

I have a systemd timer service which runs a script every 5 minutes to check if the monitor has been powered off. If it is powered off, it locks the screen.

But I'm having some problems with the users and permissions. It seems the script must be run as sudo to query the monitor's power state, but this causes the xsecurelock to require the root password to unlock the screen. How can I fix this?

I should say: I want to keep this approach and the use of xsecurelock since this is working on my other PCs. Needing sudo to query the power state seems peculiar to this PC.

1. Systemd service

Description=Check if Monitor is switched off and run xsecurelock
After=network.target

[Service]
User=dave
Environment=XAUTHORITY=/home/dave/.Xauthority
Environment=DISPLAY=:0
Type=simple
ExecStart=/home/dave/monitor_check.sh --debug
StandardOutput=journal
StandardError=journal
Restart=no
[Install]
WantedBy=multi-user.target

2. Script

XSECURELOCK_SAVER=saver_xscreensaver
export XSECURELOCK_SAVER
echo "The value of XSECURELOCK_SAVER is: $XSECURELOCK_SAVER"

    state=$(ddcutil getvcp D6 2>&1)
        echo "$state"
    sleep 2

    if [[ "$state" == *"Display not found"* ]]; then
        echo "Monitor is off, executing command..."
        exec xsecurelock
        break
    else
    echo "Display is found, nothing to do."
    fi

I need to get aware when my android device notifies me about new message, call, whatsapp, everything and I'm not looking at my mobile device screen. It happens many times in a day that I go and check it manually. While I'm looking at my PC's screen, I may miss many of them. The office policy is to silent mobile devices. I may be in meetings, etc. Any cause may cause I get involved with many other things and don't remember to check my notifications. While it may be very good solution if I have something on PC's screen to communicate with the mobile and show me that I have new notifications, eg. an icon in notification area may get red/green or something. My mobile device use data for communicating with the internet and we've no wifi at office. LAN is completely in another network. Is there any possibility for this? I'm using Ubuntu mate 24.04.

The GUI trackpad settings for my Lenovo 16IAX7 running ubuntu 24.04 6.8.0-48-generic don't seem to affect the scrolling behavior. (Neither do the mouse settings). I am using the Gnome DE and Mutter WM. I've gone through the post here but this doesn't seem to be entirely relevant to my case as (for instance) I don't see a natural scroll option. How would I get the GUI to work, or get natural scrolling running some other way?