Posts tagged with “bash”

KDE Shenanigans: Playing a random video from Dolphin

Dolphin, the KDE file manager, is great, and has grown to become my favorite file manager of all time. It's super customizable, and a joy to use, which is more than I can say for the Windows equivalent. I do a fair amount of file management, so having a good tool for this is important, and when it's extensible like Dolphin, that's when it really starts to shine.

I recently got the idea to make a script that will play a random video file from a given directory tree. Some possible use cases for this is to play a random episode of a TV show, or a random home recording stored on your computer. Making the script itself was fairly straight-forward, but I don't want to open up the terminal to launch my script every time I want to use it, and I have enough keyboard shortcuts for things already (the most important one being Meta+Z, which plays a rimshot sound effect, much to the amusement of everyone I know).

Naturally, I started looking into integrating this into Dolphin. Initially, I wanted to make a custom toolbar button, but it turns out that isn't possible. What you can do however, is make a KDE Service Menu! These live in the context menu that pops up whenever you right-click things. They are really easy to create as well, you just pop a suitable .desktop file in the right directory, make it executable, and presto! You got yourself a context menu item! Let's see how to accomplish this.

Making the script

First of all, let's make the script itself. There are many ways to go about this, and I just went with the most straight-forward way I could think of; recursively reading the files of the current directory, filtering them on extension, and picking a random one out of the list.

playrandomvideo.sh:

#!/bin/bash
shopt -s nullglob nocasematch
matches=$(find . -print | grep -i -E "\.(webm|mkv|ogv|mov|avi|qt|ts|wmv|mp4|m4v|mpg|mp2|mpeg|mpe|mpv|flv)$" --color=none)
IFS=$'\n'
read -r -d '' -a matchedFiles <<< "$matches"
numFiles=${#matchedFiles[@]}

if [[ "$numFiles" -gt "0" ]] ; then
    rand=$((0 + $RANDOM % $numFiles))
    randFile=${matchedFiles[${rand}]}
    xdg-open "$randFile"
    exit 0
else
    kdialog --sorry "No videos found in the current directory tree."
    exit 1
fi

Note that if you use some esoteric video format that is not included in the regex pattern on line 3 of the script, you can just add it. You can also replace the list of file extensions entirely if you want to adapt the script to opening a different type of content; why not live life on the cutting edge and replace it with ppt|pptx|odp, so the next time you have a presentation at work, you won't know what you're presenting until you start it? Way to keep yourself on your toes.

Place it somewhere safe, like /opt/scripts, and make it executable with chmod +x playrandomvideo.sh.

Making the service menu

Prior to doing this, I didn't know how to create service menus, but KDE has great documentation on how to do that.

First, find the location of service menus on your system, and cd into it. Create playrandomvideo.desktop, and make it executable.

$ qtpaths --locate-dirs GenericDataLocation kio/servicemenus
/usr/share/kio/servicemenus
$ cd /usr/share/kio/servicemenus
$ sudo touch playrandomvideo.desktop
$ sudo chmod +x playrandomvideo.desktop

Note that if your path is in your home directory, you do not need to use sudo to touch and chmod the file.

Now open the file in your favourite text editor, and populate it with the following:

playrandomvideo.desktop:

[Desktop Entry]
Type=Service
MimeType=inode/directory;
Actions=playRandomVideoFromHere
X-KDE-Priority=TopLevel

[Desktop Action playRandomVideoFromHere]
Name=Play random video from here
Icon=media-playback-start
Exec=cd "%u"; /opt/scripts/playrandomvideo.sh

Change the contents of the last line to match where you placed the script we made earlier.

The line X-KDE-Priority=TopLevel is optional. If you keep it, the context menu entry will appear at the top level of the context menu, like so:

If you omit the line, the context menu item will live under a submenu named "Actions":

Done!

Now you can right click any folder, or any empty area of the current folder, and click "Play random video from here" to do just that. The video will open in your system default handler for its respective file type (using xdg-open). If no videos are found, you'll be notified via a dialog box.


Sending arbitrary files directly from Firefox to your phone

The task

Automation is great. There's just something inherently beautiful about the process of stringing together a bunch of software, services, or tools to attain a simple goal, and finding a solid solution that just works™. One automation task I've been tinkering with lately is how to send an arbitrary file directly from my browser to my phone, with as little fuss as possible. I often browse reddit or just the web in general and find a funny video or image I want to keep on my phone to send to someone, or just to easily refer to back later. If I can just click a button and nearly immediately have a copy of the resource in question available on my phone, that would be really swell.

Luckily, the world of open source software provides a multitude of ways to accomplish this task; here's how I did it.

The requirements

To follow along at home, you'll need:

  • A Linux-based computer
  • An Android-based smartphone
  • Firefox on your PC
  • The Open With addon for Firefox
  • yt-dlp (or youtube-dl or any of its forks) on your PC
  • KDE Connect on your PC (ships with the KDE Plasma desktop, or can be installed on most other DEs through your package manager)
  • KDE Connect on your phone
  • Optional: libnotify for notifications, pulseaudio for audio alerts

The solution

First, install the Open With addon into Firefox. Once that's done, follow the instructions it gives to set it up, it requires a helper script to be able to launch external resources from within Firefox. Install the KDE Connect app on your phone, and pair it with your computer. Now that that's set up, you can make a couple of scripts that the Firefox addon will run whenever you invoke it. The first one is specifically for video content, the second is for files.

send-to-phone-yt-dlp.sh:

#!/bin/bash
deviceName="Fold 3"
ytdlpPath="/opt/yt-dlp"
savePath="/home/lars/Downloads/%(title)s [%(id)s].%(ext)s"
errorSound="/usr/share/sounds/ubuntu/notifications/Slick.ogg"
successSound="/usr/share/sounds/ubuntu/notifications/Positive.ogg"

notify-send -u low "yt-dlp" "Starting download with yt-dlp..." --icon=camera-video
ytdlpOutput=$($ytdlpPath -o "$savePath" "$1" 2>&1)

if [[ "$?" -gt 0 ]] ; then
    ytdlpOutput=$(echo $ytdlpOutput | tail -n1)
    notify-send -u normal "Error" "${ytdlpOutput}" --icon=emblem-warning
    paplay $errorSound
else
    notify-send -u normal "Success" "Download successful! ($1)" --icon=emblem-success
    fileNameResult=$($ytdlpPath --get-filename -o "$savePath" "$1")
    kdeconnect-cli -n "$deviceName" --share "$fileNameResult"
    paplay $successSound
fi

send-to-phone-wget.sh:

#!/bin/bash
deviceName="Fold 3"
saveDir="/home/lars/Downloads"
errorSound="/usr/share/sounds/ubuntu/notifications/Slick.ogg"
successSound="/usr/share/sounds/ubuntu/notifications/Positive.ogg"

notify-send -u low "Download" "Starting download with wget..." --icon=unknown
cd $saveDir
dlFilename=$(wget "$1" 2>&1 | grep Saving | cut -d ' ' -f 3 | sed -e 's/[^A-Za-z0-9._-]//g')

if [[ "$?" -gt 0 ]] ; then
    notify-send -u normal "Error" "Download failed!" --icon=emblem-warning
    paplay "$errorSound"
else
    notify-send -u normal "Success" "Download successful! ($1)" --icon=emblem-success
    kdeconnect-cli -n "$deviceName" --share "$dlFilename"
    paplay "$successSound"
fi

You'll need to do some changes to these scripts depending on your environment:

  • Change the value of deviceName to the registered name of your phone in KDE Connect
  • Change the value of ytdlpPath to point to the yt-dlp binary on your system
  • Change the value of savePath to point to your preferred save location and filename of the videos downloaded by yt-dlp
  • Change the value of saveDir to point to your preferred save directory of the files downloaded by wget
  • Change the value of errorSound and successSound to the appropriate paths if you are not running a flavour of Ubuntu, or remove them altogether if you do not want audio feedback. In that case, remove all lines starting with paplay as well
  • Replace the lines starting with paplay with appropriate commands for your audio system if you do not use PulseAudio, but still want audio feedback
  • Remove the lines starting with notify-send if you do not want notifications or if you don't have libnotify installed

Don't forget to make the scripts executable! (chmod u+x /path/to/script.sh). Place them somewhere safe, i like /opt/scripts.

The next step is adding these scripts inside the Open With addon for Firefox. Click the Open With button in the toolbar, and click "Open With options". Click "Add browser". Fill in a name, and the path to the script with "%s" at the end, this is replaced with the URL when the script is invoked. Pick a custom icon if you'd like.

Repeat the same process for the other script, and you should end up with these two entries:

And that's really all there is to it. Now, whenever you are on a page that has a video you want to download and send to your phone, you can click the Open With toolbar icon, then "Send video to phone". If you're viewing a file, click the corresponding Open With item. This also works for links; If there's a link to an image or a file you want to download and send to your phone, just right click the link, go to "Open With", and click "Send file to phone (wget)", or pick the corresponding option if the link is to a video page.

Closing thoughts

Being able to send any video, picture or arbitrary file to my phone in two clicks is really convenient! The Open With addon is also really great for automating many other tasks that involve URLs, here are a couple of examples:

  • If a page doesn't behave/work in Firefox, I wanna open it in another browser. I have the Flatpak version of Ungoogled Chromium installed for that, but opening that, manually copying the URL from FF, tabbing over to Chromium, then pasting it in the address bar is a chore. Just add it to Open With: flatpak run com.github.Eloston.UngoogledChromium %s, and two clicks will open your current URL in the other browser (Note that this will NOT work if Firefox is running as a Flatpak, as flatpak run executed from within another flatpak will silently fail, in my experience, even with full permissions).
  • If I wanna send a link to JDownloader instead of opening it in Firefox, I can just add JDownloader to Open With, with the command /bin/sh /opt/jd2/JDownloader2 %s

I'm sure there are many other uses for this approach as well, get creative!


Bash script: Randomize filenames in a directory

Continuing on the theme of file management from my last post: This script takes a folder of files and randomizes all filenames, whilst keeping the filename extension. This is useful if you're sorting by name, and want to have the files presented in a random order. Some possible use cases are a folder of pictures you intend to post to a blog, do further processing on, and the order and names of the files aren't important.

Usage: cd to the directory that contains the files you wish to randomize the filenames of, then run the script.

randomize_filenames.sh:

#!/bin/bash
# Randomize file names in current working directory, keeping the filename extension
# Modified from: https://unix.stackexchange.com/a/6553
# Ignores dotfiles and subdirectories

find . -type f -not -path '*/.*' |
while read -r name; do
  ext=${name##*/}
  case $ext in
    *.*) ext=.${ext##*.};;
    *) ext=;;
  esac
  newName=`mktemp --dry-run XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX`
  mv "$name" "$newName$ext"
done

Bash script: Sort a large directory into alphabetical subdirectories

Every so often, I download something off the internet that is delivered as a multitude of files in a root folder, with no kind of sorting applied to it. Big sets of games for the PICO-8 engine, perhaps, or an assorted collection of music files. Often times these sets, especially if they are games, will go onto an embedded device like a modified games console, a flash cart, or onto an emulation handheld, which makes browsing 7349 files a nightmare using only a D-pad on a small screen. The device might not even support showing more than a specific number of files in one directory.

The solution? This Bash script! The script will create folders named 0-9 and A through Z, and move all files that start with a number or letter into its respective folder. At the end, you'll end up with a clean directory structure you can copy to your storage media, and not have to flick through hundreds of pages just because you want to play something that starts with a W.

Usage: cd to the directory containing your unsorted files, then execute the script. Files that do not start with a number or letter will not be moved.

foldersort.sh:

#!/bin/bash
shopt -s nocasematch
dirs=(0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z)

for file in *
do
    for dir in "${dirs[@]}"
    do
        mkdir -p "$dir"
        if [[ $file =~ ^[$dir] ]]
        then
            mv "$file" "$dir"
            break
        fi
    done
done