Sublime text: How to do sentence case (capitalize the first letter of a sentence)

You can use this regex:

find

(^|\.\s|…\s)([a-z])

and replace with

\1\u\2

Explanation:

1. The first find group (parénthesis group) captures a line beginning or a dot followed by a space or three dots character followed by a space.
2. The second group captures a letter.
3. In the replace expresion \1 and \2 refer to the captured groups.
4. \u means translate one character to uppercase.
5. This capitalizes lines starting with a character and sentences starting after other sentences.

Find:

<h4>(.)(.*)</h4>

Replace:

<h4>\u\1\L\2</h4>

That would make

<h4>This Is A Demo</h4>

into

<h4>This is a demo</h4>