I'm very new to Linux and scripting; been using Fedora 13 for about a month now and playing around with scripting for just about two weeks. But my problem is that I don't like to just install things without understanding them. I understand what the script does but not what the commands within the script tell it to do.

For the most part I haven't a clue about scripting and want to learn. I found this script online and I've been able to find a few of the commands online that explain a bit about what is going on in the script but for the most part I haven't the foggiest as to how the script works.

I'm hoping someone can help me understand what is actually happening in this script. I know that I can set the computer to warn me when my disk space is getting low but lets face it, where is the fun in that.

#!/bin/bash
# comment
ADMIN="myemail@itsme.com"
ALERT=90
df -H | grep -vE '^none' | awk ' { print $5 " " $1 }' | while read output;
do
#echo $output
usep=$(echo $output | awk ' { print $1 }' | cut -d'%' -f1 )
partition=$(echo $output | awk '{ print $2 }' )
if [ $usep -ge $ALERT ]; then
echo "Running out of space \"$partition ($usep%)\" on$(hostname) as on $(date)"|
mail -s "Alert: Almost out of disk space $usep" $ADMIN
fi
done

Simplest way is run command on shell which are defined in script.

BTW there are some variables and logic is used.

Good docs that cover shell programming:

http://rute.2038bug.com/index.html.gz
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html
http://www.tldp.org/LDP/abs/html/
http://linux.die.net/man/