Red Hat / Fedora :: Bash Script To Monitor Server Load / Mail From Command Line

I am attempting to write a very basic script that monitors a server's load and automatically emails an administrator upon the load reaching a certain threshold...

1.) `uptime | awk -F ' ' {'print $10'} | cut -d ',' -f1 | awk -F '.' {'print $1'}` -- the output from this command results in a decimal figure, so when that value is parsed and placed in an if statement, the value is not seen as a number. load-monitor.sh: line 9: [: 4.96: integer expression expected/How can I allow a number like "4.56" to be seen as an actual number within the if statement and be compared to 4, for instance?

2.) I am running a cPanel server on CentOS 5.4 -- when I run mail -s "SUBJECT" $EMAILADDRESS the command just hangs, and stracing the process shows it stuck on a read syscall.

3.) If I wanted to write this script in PHP, I have one primary confusion -- how can I mimic the functionality of obtaining the output from uptime via awk, etc. so that I can determine what the server load is at a given time? Which PHP function(s) would assist in that regard?