What is required on ESXi 5.5 CLI to run scripts

I want to run a script to to check for hardware failure, but when I create the script using vi and I type #chmod +x script.sh, and #./script.sh I receive "./script.sh: not found."

My guess ESXi 5.5 is not fully bash shell, therefore all Linux commands will not run. What program do I need to install so I can run scripts on ESXi CLI?

Thank you for your time.