RegEx

Simple Regular Expressions parser in C.

You can test if a string matches a regular expression

Usage

See the test.c file to understand how you can use the project

Here is a simple example

#include <stdio.h>
#include "regex.h"


int main(int argc, char* argv[])
{
    char* test_string = "test@gmail.com"

    if (regex(test_string, "^.*@(gmail|yahoo|microsoft).com))
        printf("This mail is good\n");
    return 0;
}

Installation

Clone the repository and :

> make all   # compile lib and test
> make test  # compile test
> make lib   # compile lib
> make clean # delete object files and executables

Features

For now, not every regex feature is implemented.

Only thoses are working fine :

• '.' any char
• '*' multiplier 0 to any
• '+' multiplier 1 to any
• '?' multiplier 0 to 1
• '{nb}' multiplier to nb
• '[abc]' choice in char
• '[a-z]' choice in char with interval
• '(ab|cd)' choice in word
• '^' begin char
• '$' end char
• '\d' digit
• '\D' not a digit
• '\w' word character
• '\W' not a word character

Limitations

• need to escape antislashes for \d etc : '\d' and so we cannot escape antislash as a whole
• no support for inverser in [] or ()
• no support for multiplier after a character class or a [] or ()
• no support for [-] with $
• no support for {2,} or {2,3}
• no support for greediness and lazyness in multipliers (greedy by default)
• no support for \s, \S
• no support for escaping normal characters
• no support for referencing group words (\1, \2)