checking avaliable disk space question

[Gregory Tomalikzcard00f]

Hello everyone,

I am writing a shell script to install some 3rd party software on
Solaris 2.6. I want my shell script to check how much space is
available on disk and compare it to the size of my program , after that
it should return if i have enough space to install it or not .
Unfortunately i am not sure how to do that since all the commands that i
know (du , df ) don't return a value that i can compare my value with .
If you know how to do that , please help and post it or email to
gtom...@hotmail.com
Thank you
- Gregory