Ubuntu – How to run a sh script targeting X11-settings on login?

For this case I am going to imagine a scenery. First of all let's say I need a script to open a web browser in certain Youtube Video(s) and each time it opens on boot I need the videos to be played with a random different duration.

First of all let's create the file, I am calling this "youtuviewer.sh", inside of which I am going to set this portions of code:

#!/bin/bash
chromium-browser http://www.youtube.com/watch?v=7bLaLJ51rRk http://www.youtube.com/watch?v=OxYSaT_NfjQ &
n=$((RANDOM%90+30))
echo $n
sleep $n
killall chromium-browser
echo "all done!"

I explain it quickly:

1. Line 1: The executable will invoke bash to interpret the instructions after which
2. Line 2: chromium-browser will run (it can be replaced by firefox or any other web browser). The browser will open the youtube links in the list in separated tabs, the list should be separated by a space. The ampersand (&) will instruct that after executing that line, the rest of the script should be executed and the chromium-browser instance should be left running meanwhile.
3. Line 3: We are going to generate a random number, between 30 and 90 and store it in a variable called "n". This will be the number of seconds that we are going to use in the next lines.
4. Line 4: We write on the terminal how many seconds will be used based on the random number.
5. Line 5: We make the script to "sleep" the "n" number of seconds.
6. Line 6: We kill chromium-browser in order to continue. This line will be executed only after Line 5 finishes waiting ("sleeping") the amount of seconds stored on the "n" variable.
7. Line 7: We celebrate saying "all done!" in the terminal.

A more complex example can be made with this 7 lines, indeed. You can make it in just one line, everything depends on what you wish to achieve.

We are going to set execution permissions to the file via your favorite file browser (nautilus comes to my mind) or via terminal. See this: How do I run .sh files?

Now we need to setup the file to be run on boot, we can achieve this via cron (see this: How do I set up a Cron job?) or by using the "Startup applications" dialog (see this: How to add application to startup application menu?).

This is the simplest way I find to do what the edits by @ImaginaryRobots let's see.

If you need further assistance don't hesitate to let us know.

Good luck!

A simple way of doing that is to add those lines to rc.local in your system.

For that you need root or sudo rights. You can edit the file with your favourite text editor, eg vim:

vim /etc/rc.local

(sleep 20
echo 'cpu limit bomi player at 40%'
cpulimit -v -e bomi -l 40) &

The first line tells the the computer to wait 20 seconds, the other 2 lines are from your script and the & at the end tells the computer to run that in a sub shell so that your computer does not wait for the function to end and will continue with boot.

You should add those lines anywhere before the exit 0 call at the end of that script since that will make it exit and ignore any lines after that.