Here

What is this?

Here or Libhere is a C-library which implements regular expressions in a simple and straightforward way.

"Here" is a sub-project from Hefesto project and it can be understood as Hefesto's Regular Expressions.

This library is not POSIX compliant because my main goal in this project is to keep the things simple and not bloated.

How to build here?

In order to build "here" you need to use Hefesto.

After you had Hefesto installed on your system just type hefesto. Being inside the libhere's src sub-directory. Something like:

root@moloko:~/here# cd src
root@moloko:~/here/src# hefesto

If all works a ".a" file will be within the src/lib sub-directory. Now you can use it to link the libhere against your projects.

How to use libhere within my code?

Basically libhere exposes for you functions for matching and replacing data.

If you need to match something, in general you should do:

(...)

#include <here.h>

(...)

here_search_program_ctx *search_program = NULL;
here_search_result_ctx *search_result = NULL;
char error_messages[4096];

(...)

search_program = here_compile(".*6655321.*", error_messages);

if (search_program == NULL) {
    //  If you don't want to know details about compilation errors
    //  just pass NULL instead of a message buffer to here_compile()
    //  function.
    printf("Regex compile ERROR: %s\n", error_messages);
    exit(1);
}

search_result = here_match_string(user_data_buffer, search_program);

if (here_matches(search_result)) {
    printf("Pattern found.\n");
    del_here_search_result_ctx(search_result);
}

del_here_search_program_ctx(search_program);

(...)

If you need to replace something you should do:

(...)

#include <here.h>

(...)

here_search_program_ctx *search_program = NULL;
here_search_result_ctx *search_result = NULL;
char *output = NULL;
size_t output_size = 0;
int replacements = 0;

(...)

search_program = here_compile("6655321", NULL);

if (search_program == NULL) {
    printf("The supplied regex has errors.\n");
    exit(1);
}

replacements = here_replace_string(user_data_buffer, search_program, "Alex", &output, &output_size);

if (replacements > 0) {
    printf("%d replacements had done -> %s\n", replacements, output);
}

del_here_search_program_ctx(search_program);

(...)

From here everything is simple! ;)

Enjoy!