#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <math.h>
#include <string.h>

#define BUF 1000

int cmp (const void *p1, const void *p2);
void error(char *s);

int main(int argc, char **argv) {
if (argc == 1) return 1;
int f, d;
size_t k = BUF, i = 0;
char err[] = "Can't open file\n",
err2[] = "Not enough memory\n";
double *a;
if ((f = open(argv[1], O_RDONLY)) < 0) error(err);
a = malloc(k*sizeof(double));
if (a == NULL) error(err2);
while ((d = read(f, &a[i], BUF*sizeof(double))) > 0) {
i += (size_t) d/sizeof(double);
if (i == k) {
k += BUF;
a = realloc(a, k*sizeof(double));
if (a == NULL) error(err2);
}
}
qsort(a, i, sizeof(double), cmp);
for (size_t j = 0; j < i; j++)
write(1, &a[j], sizeof(double));
free(a);
close(f);
return 0;
}

int cmp (const void *p1, const void *p2) {
double a = *(double *) p1, b = * (double *) p2;
if (fabs(a) > fabs(b)) return 1;
if (fabs(a) < fabs(b)) return -1;
if (a > 0) return -1; else return 1;
}

void error(char *s) {
write(2, s, strlen(s));
exit(1);
}