On Linux, I use stat --format="%s" FILE, but Solaris I have access to doesn't have stat command. What should I use then?

I'm writing Bash scripts, and can't really install any new software on the system.

I've considered already using:

perl -e '@x=stat(shift);print $x[7]' FILE

or even:

ls -nl FILE | awk '{print $5}'

But neither of these looks sensible - running Perl just to get file size? Or running 2 commands to do the same?