niftest.c

/* niftest.c */
#include "erl_nif.h"
#include <unistd.h>
#include <stdio.h>

static ERL_NIF_TERM hello(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{
	int pid;
	enif_get_int(env, argv[0], &pid);
	if (pid==10 || pid==7 || pid == 1)
	{
		printf("%s\n", "Sleeping");
		usleep(100);
	}
	printf("From %d\n\r",pid);
    return enif_make_string(env, "Hello world!", ERL_NIF_LATIN1);
}

static ErlNifFunc nif_funcs[] =
{
    {"hello", 1, hello}
};

ERL_NIF_INIT(niftest,nif_funcs,NULL,NULL,NULL,NULL)