SakoDaemon's questions

I have 150+ shortcuts defined in my .bash_aliases file. Some of them are simple commands, for example:

# Opens file with default program
o () { xdg-open "$@" & disown; }

# Folder shortcuts
alias ..='cd .. && ls'

Others are calling a script that I have somewhere else on the machine, such as:

alias i3exit='~/.config/i3/i3exit.sh'

And others are larger scripts defined like the o command above, only with 30-80 lines.

What is the difference between a script defined directly as a bash function, and an alias that calls a script from a different file? Is one preferable over the other, and if so, why?

Intuition tells me that having separate script files would be better but I don't have any arguments for that.

I was looking for a way to make my laptop's special keys work with i3-wm. I ran into this post and used the script there to create my own.

This is what I came up with for the screen brightness (on my machine, valid values seem to be between 0 and 937 - anything else gives a write error):

#!/bin/bash
#
# Usage:  lcd_bright.sh <U|D> <value>
#

MODE=`echo $1 | tr '[a-z]' '[A-Z]'`
BRIGHTNESS='/sys/class/backlight/intel_backlight/brightness'
LCDVALUE=`cat $BRIGHTNESS`

if [ "$MODE" = "U" ]
then
  NEWVALUE=$(( $LCDVALUE + $2 ))
  if [ $NEWVALUE -le 937 ]
  then
      echo $NEWVALUE > $BRIGHTNESS
  else
      echo 937 > $BRIGHTNESS
  fi
else
  NEWVALUE=$(( $LCDVALUE - $2 ))
  if [ $NEWVALUE -ge 0 ]
  then
      echo $NEWVALUE > $BRIGHTNESS
  else
      echo 0 > $BRIGHTNESS
  fi
fi

And for the keyboard backlight (it has 4 levels):

#!/bin/bash
#
# Usage:  kbd_bright.sh <U|D>

MODE=`echo $1 | tr '[a-z]' '[A-Z]'`
BRIGHTNESS='/sys/class/leds/asus::kbd_backlight/brightness'
KBDVALUE=`cat $BRIGHTNESS`

if [ "$MODE" = "U" ]
then
  NEWVALUE=$(( $KBDVALUE + 1 ))
  if [ $NEWVALUE -le 3 ]
  then
      echo $NEWVALUE > $BRIGHTNESS
  else
      echo 3 > $BRIGHTNESS
  fi
else
  NEWVALUE=$(( $KBDVALUE - 1 ))
  if [ $NEWVALUE -ge 0 ]
  then
      echo $NEWVALUE > $BRIGHTNESS
  else
      echo 0 > $BRIGHTNESS
  fi
fi

I added rules in sudoers.d/ so the scripts don't require a password, and the scripts are owned by root and have permissions set to 0754.

My i3 configuration for them is as follows:

# screen brightness control
bindsym XF86MonBrightnessUp exec sudo /home/ioana/.config/i3/lcd_bright.sh U 100
bindsym XF86MonBrightnessDown exec sudo /home/ioana/.config/i3/lcd_bright.sh D 100

# keyboard brightness control
bindsym XF86KbdBrightnessUp exec sudo /home/ioana/.config/i3/kbd_bright.sh U
bindsym XF86KbdBrightnessDown exec sudo /home/ioana/.config/i3/kbd_bright.sh D

While doing this, I saw that someone mentioned that such scripts pose a security risk, especially if they use an input (which mine do). I'd like to know more about what the specific security risks actually are with my scripts and what they imply.

In my laptop, I have a 128GB SSD (/dev/sdb) and a 1TB HDD (/dev/sda). Before today, I had Ubuntu 18.04 installed on a 30GB partition (sdb5) on the SSD alongside Windows 10 on a 90GB partition (sdb3).

Now I chose to install a minimal Lubuntu on the HDD for times when I just need to browse the web or do simple activities with minimal battery drain. I created an 7.5GB partition for / (sda4) as well as a 512MB swap partition (sda3) and a 5MB BIOS partition (sda2). The last one I made without really knowing what I was doing because otherwise I was getting a partition table requires a separate partition for boot loader code error. I left the biggest, sda1 partition as my data partition for all systems.

After installation finished and the PC rebooted, I was greeted by my regular Ubuntu GRUB, located on the SSD from the previous Ubuntu install. Normally I'd be happy with that result - except this GRUB doesn't seem to see the Lubuntu partition. I checked GRUB Customizer and it doesn't show up there either.

My question is: How do I make the Ubuntu GRUB from the SSD see the Lubuntu on the HDD?

I have a 128GB partitioned SSD with Ubuntu 18.04 and Windows 10 installed, and I want both systems to use the internal 1TB HDD (which has one NTFS partition) for data such as the Downloads, Pictures, Videos and Music folders which should be common between the two OSs.

In order to achieve this, I set up the HDD to be automatically mounted on boot at /mnt/sda1 (using gnome-disks), moved the stuff already in the folders on Ubuntu to the HDD and created symbolic links in /home for those folders (by using ln -s /mnt/sda1/Downloads ~/Downloads etc).

Everything seems to work fine, except all the files I moved are now owned by root and have permissions set to 777. I didn't do this manually so I assume it's a consequence of moving them to the mounted drive, hence my question: how can I change ownership and permissions for these files? I tried using both chown -R and chmod -R but neither worked (nor did they give an error message).

So I started cleaning up my /home folder and ran into a 110MB file named core:

file core
core: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style, from '/usr/bin/Xwayland :0 -rootless -terminate -accessx -core -listen 4 -listen 5 -d', real uid: 1000, effective uid: 1000, real gid: 1000, effective gid: 1000, execfn: '/usr/bin/Xwayland', platform: 'x86_64'

From what I understand from reading a bit, core dump files are supposed to indicate the state of the system at the time of an application failure, for the sake of figuring out what went wrong.

My question is, is it common for Xwayland to generate such core files or should I be worried that this is pointing to a serious issue with my 18.04 installation (updated from 17.10, if it matters)? And, as a user who is not familiar with core dump files, is there any simple way to figure out what exactly went wrong in case it's not a minor issue?

So I've been using the command duplicity ~ gdocs://my_folder_here to back up my /home folder to Google Drive periodically, and recently ran into the --progress argument that is supposed to show me the progress of the backup. However, when I tried using it, the result was very different from what I expected: it just keeps printing an empty loading bar every three seconds and ETA Stalled! and eventually the 100% bar when the backup completes.

Is there any way for me to fix this?

Ever since upgrading from 17.10 to 18.04, I've struggled with this odd issue: when the laptop wakes up from sleep and I enter the password, it freezes - only shows me the default Ubuntu purple screen and an immovable cursor that doesn't look like my theme-set cursor.

I had a problem with 17.10 as well, but not as annoying - when waking up from sleep, I couldn't move the cursor for about 15 seconds, but otherwise everything worked fine.

Another problem that may be related but that I cannot reproduce: sometimes (while using the computer), I see the "Computer will suspend due to inactivity" notification and then it suspends itself. Usually, when trying to wake it back up, what I mentioned above happens, but once something else happened: it managed to wake up, but my session was gone, as if I had just rebooted.

I have an ASUS ZenBook UX410UQ.

I installed the System Load Indicator GNOME extension on my Ubuntu 18.04, but for some reason, instead of showing a proper graph for CPU usage, it only shows a very thin line that seems to be a small portion of the actual graph. If I hover over it, the proper graph shows. How to make it show the whole graph all the time?

I have Ubuntu 18.04 and set the Scaling Factor in Tweaks to 1,10 because the 1920x1080 resolution makes stuff on my screen look a bit too small for my taste. That toggled this stickman icon, which now seems to not want to go away from my Panel unless I disable "Large Text".

Is there any way to hide this icon while keeping my settings?

I have Ubuntu 18.04 (updated from 17.10 where I had the same problem), and when I use it with Wayland, I cannot use any screen capturing/recording apps. For instance, when I try to take a screenshot with Shutter, I get a weird pattern instead of what's actually on my screen:

I know I can just switch to GNOME/Ubuntu on Xorg, but sometimes that's not an option. Is there a fix for this? Or a certain app that works as it should on Wayland?

I installed the latest Eclipse as per the instructions here, and the icon shows fine in the launcher, but shows as a blank icon with an exclamation mark when using ALT+TAB to switch between applications. Should I copy the eclipse.xpm file to another folder other than usr/share/pixmaps/ so the switcher can see it, or what should I do?

Image: Switching between apps with ALT+TAB:

versus launcher icons: