Building Lexical Analyzer using lex tool

Question

I am trying to learn how to use the lex tool to create a Lexical Analyzer. Now I've downloaded a couple of files that says LEX or FLEX but I am having trouble even starting them and the best part, the website doesn't explain it at all. Then I tried googling for any lex tool that may help me build a Lexical Analyzer I keep getting flex by adobe to create mobile apps. Now my Question is two fold Where can I find a Lex tool to start working and can I get any tutorials (IDE based or not) just for me to start doing something. Thanks.

Answer 1

This question has been answered in the comments by @Marcin Łoś and @Thomas Padron-McCarthy, but remains in the unanswered question queue.

(See Question with no answers, but issue solved in the comments (or extended in chat) )

The Flex lexical analyser can be downloaded (both as source or binary) from https://github.com/westes/flex/releases

There are many good online tutorials you can find by internet search. This one: http://epaperpress.com/lexandyacc/download/LexAndYaccTutorial.pdf was recommended. I also like this one: http://aquamentus.com/flex_bison.html

There are also many helpful demonstrations on YouTube.