bash

Remove Disabled Snaps.

 in Bash / GNU/Linux  tagged bash / clean up / free space / GNU/Linux / snap / ubuntu by 
LANG=C snap list --all | awk '/disabled/{print $1" --revision "$3}' | xargs -rn3 sudo snap remove;

Let us break down the command for you:

  1. LANG=C sets the language to English (C locale), which can be helpful to ensure consistent behavior across different systems with different default languages. We used this to make sure that the word disabled will appear for disabled snaps and not some other translation.
  2. snap list --all lists all installed snaps (i.e., packages) along with their details. The output of this command is piped to the following command.
  3. awk '/disabled/{print $1" --revision "$3}' searches for lines in the output that contain the word “disabled” and prints the first field (i.e., the name of the snap) followed by the string “–revision” and the third field (i.e., the revision number). This output is piped to the next command.
  4. xargs -rn3 sudo snap remove takes groups of three arguments from the input and runs the command snap remove with those arguments. In this case, the first argument is the name of the disabled snap; the second argument is the string “–revision”, and the third argument is the revision number. This will remove all disabled snaps and their associated revisions.

So, in summary, the command searches for all disabled snaps on the system, extracts their name and revision number and then removes them using the snap remove command. This is a very useful command to free up some space without losing data or functionality.

Two Signal accounts on Ubuntu 22.04LTS

 in GNU/Linux  tagged bash / dual accounts / GNU/Linux / multiple accounts / signal / signal desktop / ubuntu by

Signal is a widely used messaging app that prioritizes user privacy and security. However, there may be times when one needs to use multiple Signal accounts on the same device. In this blog post, we will discuss the problem of needing two Signal accounts on Ubuntu 22.04LTS and how to solve it by installing the beta version.

The Problem:

Let’s say you have two Signal accounts, one for personal use and the other for work. Unfortunately, Signal does not provide a built-in feature for running multiple accounts on the same device. This can be a frustrating problem for Ubuntu 22.04LTS users who want to use multiple Signal accounts. Fortunately, there is a solution, and that is to install the beta version of Signal on your device.

Installation Steps:

  1. Open the Terminal.
    The first step is to open the Terminal by clicking the Terminal icon or pressing the “Ctrl+Alt+T” keys.
  2. Add the Signal repository.
    To install the beta version of Signal on Ubuntu 22.04LTS, you need to add the Signal repository to your system. Run the following command to add the repository:

echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/signal-desktop-keyring.gpg] https://updates.signal.org/desktop/apt xenial main' | sudo tee -a /etc/apt/sources.list.d/signal-xenial.list;

  1. Add Signal’s public key.
    Next, you need to add Signal’s public key to your system. This key is used to verify the authenticity of the packages in the repository. Run the following command to add the public key:

wget -O- https://updates.signal.org/desktop/apt/keys.asc | gpg --dearmor > signal-desktop-keyring.gpg;
cat signal-desktop-keyring.gpg | sudo tee -a /usr/share/keyrings/signal-desktop-keyring.gpg > /dev/null;

  1. Update the package list.
    After adding the repository and public key, you must update the package list. Run the following command to update the package list:

sudo apt update;

  1. Install the beta version of Signal.
    Finally, you can install the beta version of Signal by running the following command:

sudo apt install signal-desktop-beta;

This will install the beta version of Signal on your system, which you can use to run multiple Signal accounts.

Conclusion:

In conclusion, running multiple Signal accounts on Ubuntu 22.04LTS can be a problem. However, installing the beta version of Signal can solve this problem. Following the above installation steps, you can easily install the beta version of Signal on your device and use multiple Signal accounts without hassle.

Linux: Delete all files that are older than X days

 in Bash / GNU/Linux  tagged bash / ctime / delete / exec / find / GNU/Linux / mtime by

The command find /data/ -type f -mtime +15 -exec rm -f '{}' \; is used to search and delete all the files in the “/data/” directory that have a modification time of more than 15 days old. The following is an explanation of each part of the command:

  1. “find /data/” – This specifies the directory that the search will start from; in this case, it’s the “/data/” directory.
  2. “-type f” – This option specifies that the search should be limited to files, not directories.
  3. “-mtime +15” – This option specifies that the files should be older than 15 days based on the modification time. The “+” sign indicates that we are looking for files older than 15 days.
  4. “-exec rm -f ‘{}’ \;” – This option is used to execute a command on the files found. The command “rm -f ‘{}'” is used to delete the files and the “{}” is a placeholder for the files that are found. The “” at the end of the line is used to escape the semicolon and avoid a syntax error.

The “find /data/ -type f -ctime +15 -exec rm -f ‘{}’ \;” command is similar to the above command, but it searches for files based on their creation time instead of modification time. The “ctime” option specifies that the search should be based on the file creation time instead of the modification time.

In conclusion, both commands are used to delete files in the “/data/” directory that are older than 15 days. Still, the difference is that the first command searches for files based on their modification time, while the second command searches for files based on their creation time.

Automatic generation of phone background images using ImageMagick

 in Applications / ImageMagick  tagged bash / GNU/Linux / imagemagick by
generateWallpapers.sh_Download
#!/bin/bash

#Once upon a time, there was a script that had a mission to create some wallpapers. First, it created a variable called "EXPORT_FOLDER" and assigned it the value "Wallpapers". Then, it made a new directory called "Wallpapers" where it would save the wallpapers it creates.

EXPORT_FOLDER="Wallpapers";

mkdir "$EXPORT_FOLDER";

#The script defined two variables, "FLOOR" and "CEILING" and assigned them the values of -180 and 180 respectively. It also created a variable "RANGE" which was the difference between CEILING and FLOOR + 1. Additionally, it created two variables "WALLPAPER_WIDTH" and "WALLPAPER_HEIGHT" and assigned them 1440 and 3040 respectively, which would be the size of the wallpapers it creates.

FLOOR=-180;
CEILING=180;
RANGE=$(($CEILING-$FLOOR+1));

WALLPAPER_WIDTH=1440;
WALLPAPER_HEIGHT=3040;

#The script then began its main task: a loop that would run 10 times. Within the loop, it would create a variable "RESULT" and assign it a random number using the $RANDOM variable. Then, it would use the modulo operator to calculate the remainder of dividing "RESULT" by "RANGE", and assigns the result back to "RESULT". Next, it would add "FLOOR" to "RESULT" and assigns it back to "RESULT".

for i in {1..10}
do
 RESULT=$RANDOM;
 let "RESULT %= $RANGE";
 RESULT=$(($RESULT+$FLOOR));

 #After all these calculations, the script uses the convert command from the ImageMagick suite to generate an image using the plasma:fractal with a blur of 0x2 and swirl of "RESULT" and shave 20x20 pixels from the edges. The generated image is saved to "$EXPORT_FOLDER/plasma_swirl_$i.jpg".
 convert -size "$WALLPAPER_WIDTH"x"$WALLPAPER_HEIGHT"  plasma:fractal -blur 0x2  -swirl $RESULT  -shave 20x20  "$EXPORT_FOLDER/plasma_swirl_$i.jpg";

 #Finally, the script used the convert command again to composite two other images "ByteFreaks.net_.png" and "cropped-ByteFreaks.net_.png" onto the plasma_swirl_$i.jpg and saves the result as "lock_$i.jpg" and "home_$i.jpg". And after 10 loops of all these steps, the script had successfully created 10 unique and interesting wallpapers, saving them all in the "Wallpapers" folder. The script was proud of its accomplishment and the wallpapers were enjoyed by many.

 convert "$EXPORT_FOLDER/plasma_swirl_$i.jpg"  "ByteFreaks.net_.png" -gravity southeast -geometry +333+1600 -composite "$EXPORT_FOLDER/lock_$i.jpg";

 convert "$EXPORT_FOLDER/plasma_swirl_$i.jpg"  "cropped-ByteFreaks.net_.png" -gravity southeast -geometry +0+0 -composite "$EXPORT_FOLDER/home_$i.jpg";

done

This script is written in Bash and it does the following:

  1. It creates a variable called “EXPORT_FOLDER” and assigns it the value “Wallpapers”.
  2. It creates a directory with the name of the variable “EXPORT_FOLDER” (i.e. “Wallpapers”).
  3. It creates two variables, “FLOOR” and “CEILING” and assigns them the values of -180 and 180 respectively. It also creates a variable “RANGE” which is the difference between CEILING and FLOOR + 1.
  4. It creates two variables “WALLPAPER_WIDTH” and “WALLPAPER_HEIGHT” and assigns them 1440 and 3040 respectively.
  5. It starts a loop that runs 10 times. Within the loop, it does the following:
    • It creates a variable “RESULT” and assigns it a random number using the $RANDOM variable.
    • It uses the modulo operator to calculate the remainder of dividing “RESULT” by “RANGE”, and assigns the result back to “RESULT”.
    • It adds “FLOOR” to “RESULT” and assigns it back to “RESULT”
    • It uses the convert command from the ImageMagick suite to generate an image using the plasma:fractal with a blur of 0x2 and swirl of “RESULT” and shave 20×20 pixels from the edges. The generated image is saved to “$EXPORT_FOLDER/plasma_swirl_$i.jpg”
    • It then uses the convert command again to composite two other images “ByteFreaks.net_.png” and “cropped-ByteFreaks.net_.png” onto the plasma_swirl_$i.jpg and saves the result as “lock_$i.jpg” and “home_$i.jpg”

In short, this script creates 10 jpg images by applying a swirl effect on a fractal plasma image and compositing two other images onto it. These images are saved in the “Wallpapers” folder.