basename.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 <stdio.h>
  16 #include <string.h>
  17
  18 #define VERSION "0.01"
  19
  20 int main(int argc, char* argv[])
  21 {
  22
  23     // flag parsing
  24     int arg = 0;
  25     for (arg = 1; arg < argc; arg++)
  26     {
  27         if (strcmp("--help", argv[arg]) == 0 || strcmp("-h", argv[arg]) == 0) {
  28             printf("Usage: %s [name] [suffix]\n", argv[0]);
  29             printf("\n"
  30                    "    --help              Print this message.\n"
  31                    "    --version           Show version info.\n");
  32             return 0;
  33         } else if (strcmp("--version", argv[arg]) == 0 || strcmp("-v", argv[arg]) == 0) {
  34             printf("basename (mutos) v"VERSION"\n");
  35             return 0;
  36         } else {
  37             break;
  38         }
  39     }
  40
  41     if ((argc - arg) == 0) {
  42         fprintf(stderr, "%s: missing operand\n"
  43                         "Run '%s --help' for usage.\n",
  44                         argv[0], argv[0]);
  45         return 1;
  46     } else if ((argc - arg) > 2) {
  47         fprintf(stderr, "%s: too many arguments\n",
  48                          argv[0]);
  49         return 1;
  50     }
  51
  52     char* name   = argv[arg];
  53     char* suffix = NULL;
  54
  55     // remove any trailing slashes
  56     for (size_t i = strlen(name) - 1; ; i--)
  57     {
  58         if (name[i] == '/') {
  59             name[i] = '\0';
  60         } else {
  61             // if there's no more slashes
  62             break;
  63         }
  64
  65         // reached the beginning of the string
  66         if (i == 0) {
  67             break;
  68         }
  69     }
  70
  71     if ((argc - arg) == 2) {
  72         suffix = argv[arg + 1];
  73
  74         for (size_t i = strlen(name), j = strlen(suffix); ; i--, j--)
  75         {
  76             if (name[i - 1] == suffix[j - 1]) {
  77                 name[i - 1] = '\0';
  78             } else {
  79                 break;
  80             }
  81         }
  82     }
  83
  84     // set start to zero, so that if no slash is found,
  85     // the start location is the beginning of the string
  86     size_t start = 0;
  87     for (size_t i = strlen(name) - 1; ; i--)
  88     {
  89         if (name[i] == '/') {
  90             start = i + 1;
  91             break;
  92         }
  93
  94         // reached the beginning of the string
  95         if (i == 0) {
  96             break;
  97         }
  98     }
  99
 100     for (size_t i = start; i < strlen(name); i++)
 101     {
 102         printf("%c", name[i]);
 103     }
 104
 105     // if suffix deleted the entire basename,
 106     // print the whole basename instead of
 107     // nothing
 108     if (start == strlen(name)) {
 109         printf("%s", suffix);
 110     }
 111     printf("\n");
 112
 113     return 0;
 114 }