Caplitalize(change to uppercase )first letter of each word in a line

How can you capitalize each word in a line using perl?

let say there is a file:

> cat temp
hi this is world

how can we make it

Hi This Is World

its very simple to do it in perl:

perl -pe '$_=~s/\b(\w)/\U$1/g;' your_file

if you want to do it inplace just add  a -i flag:

perl -pi -e '$_=~s/\b(\w)/\U$1/g;' your_file