Shell Programming and Scripting

#!/usr/bin/ksh
# PURPOSE: This script is going to view the top 10 largest home directory Folders, then go in each directory and list top 10 largest files.
#
#Author: Emmanuel Iroanya Jr
#Date: March 8,2012
#
##### DEFINE FILES AND VARIABLES HERE ####
WORKFILE="/tmp/homedf.work" # Holds filesystem data
>$WORKFILE # Initialize to empty
OUTFILE="/tmp/homedf.outfile" # Output display file
>$OUTFILE # Initialize to empty
THISHOST=`hostname` # Hostname of this machine
USER=`ls /home | sort -n -r | head -n 10` # Define User
counter=0 # Sets Counter to 0
######## START OF MAIN #############

cd /home
du -sk /home | sort -n -r | head -n 10 > $WORKFILE

while read $USERS

do 
du -a $USER | sort -n -r | head -n 10 > $OUTFILE
counter=counter+1
done

if [[ -s "$WORKFILE" && "$OUTFILE"]]
then
cat "$WORKFILE" && "$OUTFILE"
print
mailx -s "Home Folder Size Files" exxxxxxl_ixxxxxa@xxxxxx.com < "$WORKFILE" && "$OUTFILE"

fi

if [[ -s "$WORKFILE" && "$OUTFILE" ]]

USER=`ls /home | sort -n -r | head -n 10`

ls /home | sort -n -r | head -n 10| while read USER
do
  <the rest...>
done

if [[ -s "$WORKFILE" && "$OUTFILE" ]]

if [ -s "$WORKFILE" -a  -s "$OUTFILE" ]

du -sk /home/* | sort -n -r | awk '{print $2}' | head -10

# Wrong
counter=0      
counter=counter+1
echo $counter
counter+1

# Right
counter=0
let counter=$counter+1
echo $counter
1

# Modern syntax
counter=0
counter=$(($counter + 1))
echo $counter
1