a variation on the random wallpaper script

[cafine-fish]

i had done allot of searching and couldn't find a random wallpaper script that behaved the way i wanted it to. so i wrote my own and thought i would share it just in case some one else is looking for what i was. i am also a little proud of this being that i am not really a programmer.

first off i wanted a random wallpaper changer. there are a number of options out there to do just this. but i also wanted to be sure that all my wonderful wallpapers had equal screen time. basically i wanted to make a randomized "play list" of wallpapers to go through one at a time and then reshuffle when the last one was "played". randomizing the play list was the hard part. in the end i installed the randomize-lines package. which does exactly what i needed. so here is the code:

#!/bin/bash

#file locations using full path for crontab execution
ImagePath=/home/USERNAME/pictures/wallpaper   #directory of images to use
DataFile=/home/USERNAME/bin/wpc.data          #where to keep the list of images
TempFile=/home/USERNAME/bin/wpc.temp          #temp file to use in removing a line from the list of images

#function to make the randomized list of images
make_list ()
{
  ls $ImagePath > $DataFile  #get a list of images
  rl $DataFile > $TempFile   #mix them all up
  mv $TempFile $DataFile     #make the mixed up list the list to use
}

#function to change the wallpaper, and update the list of images
change_wall ()
{
  ImageFile=$(sed -n '1p' $DataFile)  #get the first line from the list of images
  gconftool -t string -s /desktop/gnome/background/picture_filename "$ImagePath/$ImageFile"  #change the wallpaper
  gconftool -t string -s /desktop/gnome/background/picture_options "centered" #it's how i like my wallpapers
  sed -e '1d' $DataFile > $TempFile  #remove the image we just used
  mv $TempFile $DataFile  #update the image list
}

if test ! -s "$DataFile"  #if the image list doesn't exist we make it
then
make_list
fi

change_wall               #actually change the wallpaper

copy and past the code into your text editor of choice. save it with a unique name! i used wpc(for WallPaper Changer)
be sure to change out the USERNAME to your actual user name, and make sure the directory names are correct.
make it executable by either

chmod 754 wpc

or

chmod +x wpc

and set up crontab to run it as you see fit . i go with every 10 minutes. questions? comments? suggestions? it is a forum so feel free to post a reply.

[cmulax]

Hey, im interested in running your script, but im not really sure how to set it to run every x minutes. I've tried messing around with crontab but nothings working so... sorry for a noob question but how do you set how often crontab runs a script?

thanks in advance-

[cafine-fish]

noob questions are no problem, every body had to start at the beginning at some point in time.
to set up crontab you first get to a console and type "crontab -e"
that should bring up a simple text editor with a line like "# m h dom dow command". m is for minutes, h for hours, dom for day of month, dow for d of week, command is the command it will execute. so to run the script every ten minutes you would type in "*/10 * * * * /home/user/wpc". the */10 is the important bit that tells crontab to execute /home/user/wpc every minute that is evenly divisible by ten, or 0, 10, 20, ... if you changed it to */5 it would run at 0,5,10,15, ... though if you set it to just 5 it would run the script at 5 minutes after every hour.
once you have edited crontab to your liking press ctrl+x then y to exit and save the changes.
i hope that helps. if not let me know and i will be glad to help you out the best that i can

[lykeion]

Thanks for the script. I might add that you need to install package randomize-lines to get the command rl.