SCR/SCR3.1/TP3/ex5_v2.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <math.h>

#define SIZE 1000
int search(const unsigned char * t,int start,int end, int n)
{
	pid_t p;
	int i, proc, res = 0, status, partition = ceil((start + end) / n);
	for (proc = 1; proc <= n;proc++){
		p = fork();
		if (p == 0){
			for (i = 0 + partition * proc; i < partition * (proc + 1); i++){
				if (t[i] == 0)
					exit(1);
			}
			exit(0);
		}
	}
	for (i = 0; i < n; i++){
		wait(&status);
		if (WEXITSTATUS(status))
			res = 1;
	}
	return res;
}

int main(int argc , char * argv[])
{
	int i, n;
	unsigned char arr[SIZE];
	if (argc != 2){
		printf("Usage : %s <nombre de fils à créer entre 1 et 100>", argv[0]);
		return EXIT_FAILURE;
	}
	n = (int) strtod(argv[1], NULL);
	srandom(time(NULL));

	for (i = 0; i < SIZE; i++)
		arr[i] = (unsigned char) (random() % 255) + 1;

	printf("Enter a number between 0 and %d: ", SIZE);
	scanf(" %d", &i);
	if (i >= 0 && i < SIZE) arr[i] = 0;

	if (search(arr,0,SIZE-1, n)) 
		printf("Found !\n");
	else 
		printf("Not found !\n");
	return EXIT_SUCCESS;
}