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

If Perl is an option:

perl -ne 'print uc()' file

• -n loop around input file, do not automatically print line
  
• -e execute the perl code in quotes
  
• uc() = uppercase

To print all lowercase:

perl -ne 'print lc()' file