\n between each prime in numbers.txt

primes.c

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

int is_prime(unsigned long long p){
    
	unsigned long long i; //For the loop
    
	for (i = 2; i <= p-1; i++){ //Counts to the number before p
		if (p % i == 0) { //If no remainder it divides and therefore a composite number
            //printf("0\n");
            return 0;
		}
	}
	//printf("1\n"); // If not composite, prime
    return 1;
}


void *print_prime_factors(void *arg){
    
    unsigned long long i; //For the loop
    unsigned long long *n = (unsigned long long *)&arg;
    printf("%llu: ", *n);
    for (i = 2; i <= *n-1; i++){ //Counts to the number before n
	 	if (*n % i == 0) { //Factor
	 		if (is_prime(i) == 1) { // If prime
	 			printf("%llu ", i);
	 		}
	 	}
    }
    printf("\n");
    
    return 0;
}


int main(){
    
    FILE *text; //Format needed to open a file
    unsigned long long m;
    pthread_t thread0; //Reference to the second thread
    
    text = fopen("numbers.txt", "r");
    
    int r = fscanf(text, "%llu", &m);
    while(r != EOF){ //EOF is the end of the scan by default
        if (r==1) {
            if (is_prime(m) == 1){ //If the number is a prime itself
                printf("%llu: is prime \n", m);
            }
            else {
                print_prime_factors((unsigned long long *)m);
            }
        }
        
	 	r = fscanf(text, "%llu", &m);
    }
    fclose(text);//Closes the file after using it
    
    
    if(pthread_create(&thread0, NULL, &print_prime_factors, &m)) { //Creating thread
        fprintf(stderr, "Error creating thread\n");
        return 1;
    }
    
    if(pthread_join(thread0, NULL)) { //Waiting for the thread to finish
        fprintf(stderr, "Error joining thread\n");
        return 2;
    }
    
    pthread_exit(NULL); // Exiting the thread
}