#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#define BTF_ID_FUNC_PFX         "__BTF_ID__func__"

static char *get_func_name(const char *sym)
{
        char *func, *end;

        if (strncmp(sym, BTF_ID_FUNC_PFX, sizeof(BTF_ID_FUNC_PFX) - 1))
                return NULL;

        /* Strip prefix */
        func = strdup(sym + sizeof(BTF_ID_FUNC_PFX) - 1);

        /* Strip suffix */
        end = strrchr(func, '_');
        if (!end || *(end - 1) != '_') {
                free(func);
                return NULL;
        }
        *(end - 1) = '\0';

        return func;
}

int main() {
	char *name = get_func_name("__BTF_ID__func__");
	printf("name=%s\n", name);
}