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

void* print_message( void *ptr ){
char *message;
message = (char *) ptr;
int end;
end = strlen(message) - 1;
int x;
for (x = end; x >= 0; --x) {
    printf("%c", message[x]);
}
return NULL;
}

int main(){
pthread_t thread1;
char *message = "Hello World!";
if (pthread_create( &thread1, NULL, &print_message,
(void*)message)){
fprintf(stderr,"thread error\n");
exit(1);
}
sleep(1);
exit(0);
}