Mojo one-liners are just Perl one-liners. You will use -E (or -e) to write the program. You might use -n to loop over input, or -p to do the same while printing $_ after each item, just like normal one-liners.

To get the extra Mojo goodness, add -Mojo. The name itself is a cute hack. Since -M is what loads a module on the command line, the module name is therefore ojo.