/* Copyright 2005 Daniel Cer (daniel.cer@cs.colorado.edu)

This work is licensed under the Creative Commons Attribution-NonCommercial-
ShareAlike License. To view a copy of this license, visit 
http://creativecommons.org/licenses/by-nc-sa/2.5/ or send a letter to 
Creative Commons, 543 Howard Street, 5th Floor, San Francisco, California, 
94105, USA.
*/

#include <stdio.h>
#include <errno.h>

#define INBUF_SZ 1024

/* comparison routine used with 'qsort' call */
int cmp_float(const void *a, const void *b){ return *(float*)a - *(float*)b; }
 
int main(int argc, char *argv[]) { 
  FILE *fh; char *file_name, inbuf[INBUF_SZ]; int N_items, i; float *items; 

  if (argc != 2) {
    fprintf(stderr, "Usage:\n\t%s (file with numbers to sort)\n", argv[0]);
    return -1;
  }

  file_name = argv[1]; 

  if (!(fh = fopen(file_name, "r"))) {
    fprintf(stderr, "Error opening \"%s\": %s\n", file_name, strerror(errno));
    return -1;
  }

  /* determine the number of items listed in the file */
  for (i = 0; fgets(inbuf, INBUF_SZ, fh); i++); N_items = i;
  fseek(fh, 0, SEEK_SET); 
  
  /* allocate memory to store the items */
  if (!(items = malloc(sizeof(float)*N_items))) {
    fprintf(stderr, "Error: out of memory\n"); return -1; } 

  /* read in the items from the file */
  for (i=0; fgets(inbuf, INBUF_SZ, fh); i++) sscanf(inbuf, "%f\n", &items[i]);
  fclose(fh);

  /* sort them */
  qsort(items, N_items, sizeof(float), &cmp_float);
  
  /* display the sorted items */
  for (i = 0; i < N_items; i++) {
    printf("%f\n", items[i]);
  }

  free(items);
  return 0;
}