Tiny Regular Expression Matcher

Chapter 1 of the excellent book "Beautiful Code" discusses Rob Pike's very short and elegant regex parser code. It doesn't come with all the bells and whistles of a full Perl regular expression matcher but is quite sufficient for many purposes.

I extended Rob's C code in such a way that it can handle the following regex meta-symbols:

• . - match any character
• * - the previous character is arbitrarily repeated
• + - the previous character occurs at least once
• ? - the previous character occurs once or not at all
• ^ - match regular expression only to the beginning of the text
• $ - match regular expression only to the end of the text
• \ - treat next character as a literal, even if it is a regex symbol

My library consists of just one .h and one .c file - that's why it's called "tiny".

See my website https://create.stephan-brumme.com/tiny-regular-expression-matcher/ for a live demo, code examples and a simple test suite.