fltk/src/numericsort.c

/*
 * "$Id$"
 *
 * Numeric sorting routine for the Fast Light Tool Kit (FLTK).
 *
 * Copyright 1998-2016 by Bill Spitzak and others.
 *
 * This library is free software. Distribution and use rights are outlined in
 * the file "COPYING" which should have been included with this file.  If this
 * file is missing or damaged, see the license at:
 *
 *     http://www.fltk.org/COPYING.php
 *
 * Please report all bugs and problems on the following page:
 *
 *     http://www.fltk.org/str.php
 */

#include <ctype.h>
#include <stdlib.h>
#include <FL/platform_types.h>
#include <FL/filename.H>

/*
 * 'numericsort()' - Compare two directory entries, possibly with
 *                   a case-insensitive comparison...
 */

static int numericsort(struct dirent **A, struct dirent **B, int cs) {
  const char* a = (*A)->d_name;
  const char* b = (*B)->d_name;
  int ret = 0;
  for (;;) {
    if (isdigit(*a & 255) && isdigit(*b & 255)) {
      int diff,magdiff;
      while (*a == '0') a++;
      while (*b == '0') b++;
      while (isdigit(*a & 255) && *a == *b) {a++; b++;}
      diff = (isdigit(*a & 255) && isdigit(*b & 255)) ? *a - *b : 0;
      magdiff = 0;
      while (isdigit(*a & 255)) {magdiff++; a++;}
      while (isdigit(*b & 255)) {magdiff--; b++;}
      if (magdiff) {ret = magdiff; break;} /* compare # of significant digits*/
      if (diff) {ret = diff; break;}	/* compare first non-zero digit */
    } else {
      if (cs) {
      	/* compare case-sensitive */
	if ((ret = *a-*b)) break;
      } else {
	/* compare case-insensitve */
	if ((ret = tolower(*a & 255)-tolower(*b & 255))) break;
      }

      if (!*a) break;
      a++; b++;
    }
  }
  if (!ret) return 0;
  else return (ret < 0) ? -1 : 1;
}

/*
 * 'fl_casenumericsort()' - Compare directory entries with case-sensitivity.
 */

int fl_casenumericsort(struct dirent **A, struct dirent **B) {
  return numericsort(A, B, 0);
}

/*
 * 'fl_numericsort()' - Compare directory entries with case-sensitivity.
 */

int fl_numericsort(struct dirent **A, struct dirent **B) {
  return numericsort(A, B, 1);
}

/*
 * End of "$Id$".
 */