Question

I have this code:

#include <stdio.h>
#include <pthread.h>

void* cuoco(void* arg)
{
    fprintf(stderr,"Inizio codice cuoco\n");
    fprintf(stderr,"Fine codice cuoco\n");
    return NULL;
}

void* cameriere(void* arg)
{
    fprintf(stderr,"Inizio codice cameriere\n");
    fprintf(stderr,"Fine codice cameriere\n");
    return NULL;
}

void* cliente(void* arg)
{
    fprintf(stderr,"Inizio codice cliente\n");
    fprintf(stderr,"Fine codice cliente\n");
    return NULL;
}

int main(int argc, char* argv[])
{
    void* (*routine)(void*);
    routine=cuoco;
    pthread_t thread_cuoco,thread_cameriere,thread_cliente;
    pthread_create(&thread_cuoco,NULL,routine,NULL);
    return 0;
}

And in the compiler options I insert -lpthread
But it says:
“Undefined reference to pthread_create”
I use ubuntu 10.10, so I already have pthread library installed, I can’t figure the reason of this error.

Answer 1

Use -lpthread as the last compiler flag.

example:
gcc -o sample sample.c -lpthread