I am trying to write custom sqlite3 extension in cpp.Not much hands on cpp. I have written a extension below:-

#include <regex>
#include <string>
#include <iostream>
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1

static void regex_match_func(sqlite3_context *context, int argc, sqlite3_value **argv) {
    if (argc >= 2) {
        const char *pattern = reinterpret_cast<const char *>(sqlite3_value_text(argv[0]));
        const char *target = reinterpret_cast<const char *>(sqlite3_value_text(argv[1]));

        try {
            std::regex re(pattern);
            bool match = std::regex_match(target, re);
            sqlite3_result_int(context, match ? 1 : 0);
        } catch (const std::regex_error& e) {
            sqlite3_result_error(context, e.what(), -1);
        }
    } else {
        sqlite3_result_error(context, "Two arguments required: pattern and target", -1);
    }
}

//entry point for 
#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_extension_init(sqlite3 *db, char **errmsg,
      const sqlite3_api_routines *api) {
        SQLITE_EXTENSION_INIT2(api);
        return sqlite3_create_function(db, "regex_match", 3, SQLITE_UTF8,
                                     (void*)db, regex_match_func, NULL, NULL);
      }

my scenario is that I want to run regex_match() queries on db select operation I am going to perform form go lang

example query:-

SELECT DISTINCT uid FROM regtable WHERE ( lower(reg_key) like regex_match (lower(reg_key), lower('\REGISTRY\MACHINE\SYSTEM\CONTROLSET[0-9]+\CONTROL\SECURITYPROVIDERS\SECURITYPROVIDERS'), 0)

Now when I try to load extension getting below error

sqlite> .load ./sqlite3_regex_match
Error: The specified procedure could not be found.

Can anyone help me here. This is very new topic for me.