Can I use awk to convert all the lower-case letters into upper-case?

Question

I have a file mixed with lower-case letters and upper-case letters, can I use awk to convert all the letters in that file into upper-case?

Answer 1

You mean like this thread explains: http://www.unix.com/shell-programming-scripting/24320-converting-file-names-upper-case.html (Ok, it's about filenames, but the same principle applies to files)