#!/bin/sh
#This is a shell script that checks file system capacity mounted on /home directory
#If file system is over 90% capacity, this shell script will generate notification emails sending to all users

warning()
{
 fs=$1          # first argument is the file system name
 fscap=$2       # second argument is the file system's capacity

 for user in `ls /home`

 do
   echo "File system mounted on /home directory is over 90% capacity. Please be ready for system maintainance. " | mail -s "Warning! $fs here is at $fscap capacity" user

 done

 echo "Warning: $fs is at $fscap capacity"
}

daOslg= `df -h | sed -n '/home/p' | tr -s ' ' ' ' | cut -d' ' -f1`
daOslgCap= `df -h | sed -n '/home/p' | tr -s ' ' ' ' | cut -d' ' -f5`

if ["$daOslgCap" -gt "90%"]
then
   warning $daOslg $daOslgCap
fi

      
$ ./capChecker
./capChecker: /dev/da0s1g: Permission denied           
0%: not found
[: missing ]