pthread uisng C in Unix/Linux Platform

I have written this program using pthread, in which one thread prints "Hello" and the other thread prints "World!". But after I compiled it (gcc -Wall -o pth pth.c), there is nothing printed out. Please help me to solve this, thanks a lot!
Here is the program :

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <pthread.h>
#include <thread.h>

void print_message_function( void *ptr );

int main(void)
        pthread_t thread1, thread2;
        pthread_attr_t attr;
        char *message1 = "Hello";
        char *message2 = "World";

        pthread_create( &thread1, &attr,
                (void*)&print_message_function, (void*) message1);
        pthread_create(&thread2, &attr,
                (void*)&print_message_function, (void*) message2);

void print_message_function( void *ptr )
        char *message;
        message = (char *) ptr;
        printf("%s ", message);
Who is Participating?
fremsleyConnect With a Mentor Commented:

try adding:

  pthread_addr_t status;
  pthread_join(thread1, &status);
  pthread_join(thread2, &status);

at the end of main()
The reason nothing is being printed out is that your program is exitting before the threads have a chance to do anything.

The pthread_create() calls return immediately - leaving you main() function to drop out.

Adding a delay here will give the threads time to do stuff (but not using sleep() because that pauses all threads - use usleep() or pthread_delay_np()

this is not really the best way of doing it - best to use semaphores really - there's loads of good tutorials on the net although I can't remember a URL offhand
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