implementing a website search feature using php

i want to implement a feature where a user searches with a keyword and
search results are displayed according to the keyword

or phrase entered by the user.

following are the steps i want to follow. please advice if i am missing out
any steps or i can add any step.

1. read the keyword entered by user using $search = $_PST["searchkeyword"];

2. read all the files from the root directory into a variable (as all files
will be saved in the root directory)

3. from step 2 filter and read only files with html and php extensions into
a variable

4. read the entire contents of all html and php files into a variable

5. compare $search with all the individual html and php file contents from
step 4

6. if a match is found with either html or php file then display a brief
title and brief description which will be a link to

the actual file which has the keyword.

7. display search results in a serial order as 1. Brief Title of the page 2.
Brief Title of the page

8. at the bottom of the page based on the total number of results found from
step 6 i would like to provide a link to page 1
page 2 page3 (i can decide to display only 10 results per page)

please advice.

any help will be greatly appreciated.

thanks.