How do I grep recursively on Solaris?

The old-fashioned way.

You won't get much joy running "grep -r" on SunOS, but our forefathers got by just fine with:

# find . -type f | while read file
> do
> echo $file
> grep WHATEVERYOULIKE $file
> done

This is not terribly efficient, but luckily modern SPARC processors have advanced considerably, even if modern Solaris "grep" has not.