seq.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 #include <stdlib.h>  // atoi()
  18 #include <stdbool.h>
  19
  20 #define VERSION "0.01"
  21
  22 struct {
  23     bool w;
  24 } flags;
  25
  26 char* sep = "\n";
  27 char* term = NULL;
  28
  29 void seq(char* first, char* increment, char* last)
  30 {
  31     unsigned int width = 0;
  32
  33     if (flags.w) {
  34         width = strlen(last);
  35     }
  36
  37     for (int i = atoi(first); i <= atoi(last); i+=atoi(increment))
  38     {
  39         printf("%0*d%s", width, i, sep);
  40     }
  41
  42     if (term) {
  43         printf("%s", term);
  44     }
  45 }
  46
  47 int main(int argc, char* argv[])
  48 {
  49     flags.w = false;
  50
  51     if (argc == 1) {
  52         fprintf(stderr, "%s: missing operand\n"
  53                         "Run '%s --help' for usage.\n",
  54                         argv[0], argv[0]);
  55         return 1;
  56     }
  57
  58
  59     // flag parsing
  60     int arg = 0;
  61     for (arg = 1; arg < argc; arg++)
  62     {
  63         if (strcmp(argv[arg], "-s") == 0) {
  64             sep = argv[arg+1];
  65             arg++; // don't parse separator as a flag
  66         } else if (strcmp(argv[arg], "-t") == 0) {
  67             term = argv[arg+1];
  68             arg++; // don't parse terminator as a flag
  69         } else if (strcmp(argv[arg], "-w") == 0 || strcmp(argv[arg], "--equal-width") == 0) {
  70             flags.w = true;
  71         } else if (strcmp(argv[arg], "-h") == 0 || strcmp(argv[arg], "--help") == 0) {
  72             printf("Usage: %s [first] [last]\n", argv[0]);
  73             printf("\n"
  74                    "If [first] is omitted, it is assumed to be 1.\n");
  75             return 0;
  76         } else if (strcmp(argv[arg], "-v") == 0 || strcmp(argv[arg], "--version") == 0) {
  77             printf("seq (mutos) v"VERSION"\n");
  78             return 0;
  79         } else {
  80             break;
  81         }
  82     }
  83
  84     int args_left = argc - arg;
  85
  86     switch (args_left)
  87     {
  88         case 0:
  89             fprintf(stderr, "%s: too few arguments\n",
  90                              argv[0]);
  91             return 1;
  92         case 1:
  93             seq("1", "1", argv[arg]);
  94             break;
  95         case 2:
  96             seq(argv[arg], "1", argv[arg+1]);
  97             break;
  98         case 3:
  99             seq(argv[arg], argv[arg+1], argv[arg+2]);
 100             break;
 101         default:
 102             fprintf(stderr, "%s: too many arguments\n",
 103                             argv[0]);
 104             return 1;
 105     }
 106
 107     return 0;
 108 }