How make a function to change the first letter of one English sentence to upper

I want to make a function by Lua to change the firt letter of one setence or word to upper case,
for examplle:
"i like you" to "I like you"
"woman" to "Woman"
please kindly give me your kind suggestion, thanks a lot.

For the first letter of a sentence:



To capitalize every word you can use a (rather obscure) frontier pattern, like this:



In both cases I am using a regular expression to find what we want to capitalize. Then we pass down the standard function string.upper to string.gsub, and that turns the matching text into upper case.

Thanks a lot.