Linux process monitoring daemon

Question

I'm often issuing commands that take some time. For example downloading something using a console download app. If I want to be noticed when the command has finished, I usually do something like this:

$ <do something>; echo '<do something> has finished' | osd_cat

Then I can switch to another window and do something else meanwhile. When it's done, I'll be noticed.

Now my problem is that I'm lazy. Oh well. I just don't want to type this everytime. So I wonder if there's a daemon that could watch running processes and trigger some actions when the processes finish.

I would like config options so I could have control on:

1. filtering the processes to be watched (for example, watch processes that run at least for a minute)

2. customizing the command to perform when a process has finished

Answer 1

You could try using Bash's "wait" command to write a little wrapper script Something like:

#!/bin/bash
command=$*

$command &  
wait
osd_cat "$command has finished"

The wait command causes the script to pause until all child processes have returned an exit code. You could also add a little timeout to make sure that you don't wait too long

Answer 2

How about just a simple shell script that does the long command for you. Maybe something like this:

#!/bin/sh
# tellme: run a command and tell me when it's done
if [ $# -gt 0 ]; then
    if $*; then
        echo "'$*' has finished" | osd_cat
    else
        echo "'$*' has finished with errors" | osd_cat
    fi
else
    echo "usage: $0 <command>"
fi

Then, you would just run this command:

tellme <do something>

Granted, it isn't a daemon, so I don't think it will help you for things started in the background (e.g. from cron), but it should do the job for interactive commands.