How to kick off multiple shell scripts at startup

Question

I have six shell scripts I start when I log in. The shell scripts kick off Python scripts which go out and scrape various things from the net like news headlines, weather info etc., which I add to my desktop via conky.

Problem is starting all of these shell scripts each time is a real pain.

I have looked for and tried some things but nothing seems to work.

Can someone here shed some light on the best way to do this pls. By the way I can't combine the shell scripts in a single file because they all 'sleep' for a different duration after the initial command is applied.

Thanks.

-- Edit (adding the following comments) --

All of the scripts have the following format:

#!/bin/bash

while true; do
    python /home/scott/debkaget.py > /home/scott/debka.txt
    sleep 120
done

Could that be added to the profile? I need the sleep aspect to it. I am running KDE 4.9.

Answer 1

If you're "adding to your desktop" you have a window manager running, and if you are using bash it's probably Linux. In that case you're probably best off launching your scripts into the background from an Xsession file, either ~/.Xsession or /etc/X11/Xsession or a variant. For more info try

man 5 Xsession
man 1 xinit

Answer 2

One possibility is to add the appropriate invocations to your .bash_profile or .profile file. When you run them manually, do you add an & at the end to run them in background? If so, do that in your profile too.

The main issue here is 'what happens if you've already run a login shell'. Do the 6 scripts behave sanely if there's another copy already running? Do they bother to detect that there's another copy already running.

If you're logging in at a GUI desktop, then there are ways to run programs when the desktop starts; use it to run the scripts that you're trying to deal with. For more accurate instructions (from other people), provide more information about your environment.

Answer 3

You can use this basic strategy:

• have scripts start by creating pid files as script_name.pid. Make the scripts abort if for their pid file exists
• have scripts run in the background

When you invoke from your .bash_profile (or similar) then the pid files will prevent .bashrc from winding up more processes for each new shell.

Per NormanRamsey, you will add to the XSession (or other window manager):

# Web Scrapers
runshell_yahoonews.sh
runshell_blog_disney.sh
runshell_stackoverflow_election.sh
runshell_twitter_dad.sh
runshell_twitter_origamistork.sh
runshell_blog_daringfireball.sh

Consider writing bash functions. You could have a file lib_scrapers.sh

#!/bin/bash 
pid_path = "~/.X-scrapers/"
suff = '.pid'

function pidfile_create(invoker) {
  if [ ! -e $pid_path$invoker$suff ];
  then
    # make it
    echo $$ > $invoker$suff
  else
    # alert it existance
    cat $pid_path$invoker$suff
  fi
}
function pidfile_destroy(invoker) {
  rm $pid_path$invoker$suff
  if [ -e $pid_path$invoker$suff ];
  then
    echo "$pid_path$invoker$suff could not be destroyed properly"
  fi
}

then on line 2 of each of your scrapers (e.g. runshell_yahoonews.sh). This will prevent the script for executing if a scraper is already running.

lib_scrapers.sh

if [ pidfile_create($0) ]
then
  exit
fi

at the end of each scraper, put

pidfile_destroy($0)

You could have other tradeoffs, but this sounds reasonable for what you describe.