Find the size of a single specific file

As I'm a newbie to UNIX, very newbie in fact, could anyone humour me and tell me how I'd find just the file size in bytes for a specific file?

Or at least just the specific line from the ls -a for the file - call it file1

I know this sounds bad but I don't seem to be getting very far at this one. How does one normally go about this simple task (I want to use the file size in a calculation)

sorry, i mean

ls -l file1

ls -l filename | awk '{print $5}'

if in programming lang - c
use stat command on the file

thanks for the help, I know that one was a bit of a simple question but I had so forgotten about awk for some reason