embed.c

#define _GNU_SOURCE

#include <sys/types.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <pthread.h>
#include <sapi/embed/php_embed.h>

void *thread_routine(void *data)
{
	/* Invokes the Zend Engine initialization phase: SAPI (SINIT), modules
	 * (MINIT), and request (RINIT). It also opens a 'zend_try' block to catch
	 * a zend_bailout().
	 */
	PHP_EMBED_START_BLOCK(0, NULL)

	php_printf(
		"Number of functions loaded: %d\n",
		zend_hash_num_elements(EG(function_table))
	);

	/* Close the 'zend_try' block and invoke the shutdown phase: request
	 * (RSHUTDOWN), modules (MSHUTDOWN), and SAPI (SSHUTDOWN).
	 */
	PHP_EMBED_END_BLOCK()

}

int main(int argc, char **argv)
{
    pthread_t thread;
    pthread_create(&thread, NULL, thread_routine, NULL);
    pthread_join(thread, NULL);
    
    kill(getpid(), SIGINT);

    sleep(1);

    return 0;
}

Makefile

all:
	gcc \
		$$(php-config --includes) \
		-L$$(php-config --prefix)/lib \
		embed.c \
		-lphp \
		-Wl,-rpath=$$(php-config --prefix)/lib