# a simple tokenizer
$ perl -e 'print join("|",split(/(\W)/,"Hello, World! ?")),"\n";'
Hello|,|| |World|!|| ||?

# get rid of the empty string tokens
$ perl -e 'print join("|",grep {$_}split(/(\W)/,"Hello, World! ?")),"\n";'
Hello|,| |World|!| |?

# or use plain regex
$ perl -e 'print join("|","Hello, World! ?"=~/(\W|\w+)/g),"\n";'
Hello|,| |World|!| |?