c_cpp/lib/natsort/natsort.c

   1 /* -*- mode: c; c-file-style: "k&r" -*-
   2
   3    natsort.c -- Example strnatcmp application.
   4
   5    Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au>
   6
   7    This software is provided 'as-is', without any express or implied
   8    warranty.  In no event will the authors be held liable for any damages
   9    arising from the use of this software.
  10
  11    Permission is granted to anyone to use this software for any purpose,
  12    including commercial applications, and to alter it and redistribute it
  13    freely, subject to the following restrictions:
  14
  15    1. The origin of this software must not be misrepresented; you must not
  16       claim that you wrote the original software. If you use this software
  17       in a product, an acknowledgment in the product documentation would be
  18       appreciated but is not required.
  19    2. Altered source versions must be plainly marked as such, and must not be
  20       misrepresented as being the original software.
  21    3. This notice may not be removed or altered from any source distribution.
  22 */
  23
  24 /* Partial change history:
  25  *
  26  * 2003-03-18: Add --reverse option, from Alessandro Pisani.
  27  */
  28
  29 #define _GNU_SOURCE
  30
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <getopt.h>
  35
  36 #include "strnatcmp.h"
  37
  38 #if defined(__GNUC__)
  39 #  define UNUSED __attribute__((__unused__))
  40 #endif
  41
  42 static int fold_case = 0, verbose = 0, reverse = 0;
  43
  44 static void trace_result(char const *a, char const *b, int ret)
  45 {
  46      char const *op;
  47
  48      if (ret < 0)
  49           op = "<";
  50      else if (ret > 0)
  51           op = ">";
  52      else
  53           op = "==";
  54
  55      fprintf(stderr, "\tstrncatcmp: \"%s\" %s \"%s\"\n",
  56              a, op, b);
  57 }
  58
  59
  60
  61 static int compare_strings(const void *a, const void *b)
  62 {
  63      char const *pa = *(char const **)a, *pb = *(char const **)b;
  64      int ret;
  65
  66      if (fold_case)
  67           ret = strnatcasecmp(pa, pb);
  68      else
  69           ret = strnatcmp(pa, pb);
  70
  71          if (reverse)
  72           ret *= -1;
  73
  74          if (verbose)
  75           trace_result(pa, pb, ret);
  76
  77      return ret;
  78 }
  79
  80
  81 static void usage(void)
  82 {
  83      fprintf(stderr, "Usage: natsort [OPTIONS]\n"
  84              "Performs a natural sort on standard input, and writes to \n"
  85              "standard output.\n"
  86              "\n"
  87              "  --help, -h       show help text\n"
  88              "  --verbose, -v    show comparisons\n"
  89              "  --fold-case, -f  ignore case differences for letters\n"
  90                  "  --reverse, -r        reverse the result of comparisons\n");
  91 }
  92
  93
  94 int main(int argc, char **argv)
  95 {
  96      int nlines = 0;
  97      char *line;
  98      char **list = 0;
  99      int linelen = 0, i;
 100      int c, opt_ind;
 101      size_t bufsize;
 102
 103      static struct option long_options[] = {
 104           { "verbose", 0, NULL, 'v'},
 105           { "reverse", 0, NULL, 'r'},
 106           { "fold-case", 0, NULL, 'f'},
 107           { "help", 0, 0, 'h' },
 108           { 0, 0, 0, 0 }
 109      };
 110
 111      /* process arguments */
 112      while ((c = getopt_long(argc, argv, "frvh", long_options, &opt_ind)) != -1) {
 113           switch (c) {
 114           case 'f':
 115                fold_case = 1;
 116                break;
 117           case 'h':
 118                usage();
 119                return 0;
 120           case 'r':
 121                    reverse = 1;
 122                    break;
 123           case 'v':
 124                verbose = 1;
 125                break;
 126           case '?':
 127                return 1;
 128           default:
 129                abort();
 130           }
 131      }
 132
 133      /* read lines into an array */
 134      while (1) {
 135           line = NULL;
 136           bufsize = 0;
 137           if ((linelen = getline(&line, &bufsize, stdin)) <= 0)
 138                break;
 139           if (line[linelen-1] == '\n')
 140                line[--linelen] = 0;
 141           nlines++;
 142           list = (char **) realloc(list, nlines * sizeof list[0]);
 143           if (!list) {
 144                perror("allocate list");
 145                return 1;
 146           }
 147           list[nlines-1] = line;
 148      }
 149
 150      if (ferror(stdin)) {
 151           perror("input");
 152           return 1;
 153      }
 154      fclose(stdin);
 155
 156      /* quicksort */
 157      qsort(list, nlines, sizeof list[0], compare_strings);
 158
 159      /* and output */
 160      for (i = 0; i < nlines; i++) {
 161           puts(list[i]);
 162      }
 163      if (ferror(stdout)) {
 164           perror("output");
 165           return 1;
 166      }
 167
 168      return 0;
 169 }