ls.c

   1 /*
   2     Copyright © 2013 Alastair Stuart
   3
   4     This program is open source software: you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation, either version 3 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12     GNU General Public License for more details.
  13 */
  14
  15 #include <errno.h>
  16 #include <stdbool.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20
  21 #include <dirent.h>
  22 #include <getopt.h>
  23 #include <sys/types.h>
  24
  25 #define VERSION "0.01"
  26
  27 struct {
  28     bool all;
  29 } flags;
  30
  31 int string_cmp(const void *a, const void *b)
  32 {
  33     return strcasecmp(*(char* const*) a, *(char* const*) b);
  34 }
  35
  36 int list_dir(char* dirname, bool multiple)
  37 {
  38     DIR *dp = NULL;
  39     struct dirent *ep = NULL;
  40
  41     size_t number = 0;
  42
  43     dp = opendir(dirname);
  44
  45     if (dp) {
  46         while ((ep = readdir(dp)))
  47         {
  48             number++;
  49         }
  50         closedir(dp);
  51     }
  52
  53     char* entries[number];
  54
  55     dp = opendir(dirname);
  56     if (dp) {
  57         for (size_t i = 0; (ep = readdir(dp)) && i < number; i++)
  58         {
  59             if (ep->d_type == DT_DIR) {
  60                 entries[i] = strcat(ep->d_name, "/");
  61             } else {
  62                 entries[i] = ep->d_name;
  63             }
  64         }
  65         closedir(dp);
  66     } else {
  67         return errno;
  68     }
  69
  70     qsort(entries, number, sizeof(char*), string_cmp);
  71
  72     if (multiple) {
  73         printf("%s:\n", dirname);
  74     }
  75     for (size_t i = 0; i < number; i++)
  76     {
  77         if (entries[i][0] == '.' && flags.all) {
  78             printf("%s\n", entries[i]);
  79         }
  80
  81         if (entries[i][0] != '.') {
  82             printf("%s\n", entries[i]);
  83         }
  84     }
  85
  86     return 0;
  87 }
  88
  89 void usage(char* program)
  90 {
  91     printf("Usage: %s [options]\n", program);
  92     printf("Lists directory contents.\n"
  93            "\n"
  94            "    -a, --all    Show hidden files also.\n"
  95            "\n"
  96            "    --help       Print this message.\n"
  97            "    --version    Show version info.\n");
  98 }
  99
 100 int main(int argc, char* argv[])
 101 {
 102     bool errors = false;
 103
 104     flags.all = false;
 105     static struct option long_options[] = {
 106         {"all",       no_argument, NULL, 'a'},
 107         {"help",      no_argument, NULL,  1},
 108         {"version",   no_argument, NULL,  2},
 109         {NULL, 0, NULL, 0}
 110     };
 111
 112     int c = 0;
 113     while ((c = getopt_long(argc, argv, "a",
 114                             long_options, NULL)) != -1)
 115     {
 116         switch (c)
 117         {
 118             case 'a':
 119                 flags.all = true;
 120                 break;
 121             case 1:
 122                 usage(argv[0]);
 123                 return 0;
 124             case 2:
 125                 printf("ls (mutos) v"VERSION"\n");
 126                 return 0;
 127             default:
 128                 fprintf(stderr,"Run '%s --help' for usage.\n",
 129                                      argv[0]);
 130                 return 1;
 131         }
 132     }
 133
 134     if ((argc - optind) == 0) {
 135         if (list_dir("./", false) != 0) {
 136             fprintf(stderr, "%s: %s: %s\n",
 137                          argv[0], strerror(errno), realpath("./", NULL));
 138             return 1;
 139         }
 140     } else if ((argc - optind) == 1) {
 141         if (list_dir(argv[optind], false) != 0) {
 142             fprintf(stderr, "%s: %s: %s\n",
 143                          argv[0], strerror(errno), realpath("./", NULL));
 144             return 1;
 145         }
 146     }
 147
 148     for (int i = optind; i < argc; i++)
 149     {
 150         if (list_dir(argv[i], true) != 0) {
 151             fprintf(stderr, "%s: %s: %s\n",
 152                              argv[0], strerror(errno), argv[i]);
 153             errors = true;
 154         } else if (i != argc - 1) {
 155             printf("\n");
 156         }
 157     }
 158
 159     if (errors) {
 160         return 1;
 161     } else {
 162         return 0;
 163     }
 164 }