morse.c

   1 /* Convert ASCII to morse code. Reads from stdin if provided with no argument
   2          or "-", otherwise reads from the first command line argument. Prints "?" if
   3          character is not found. */
   4
   5 #include <string.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9
  10 const char *aa[] = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
  11                                                                                 "k", "l", "m", "n", "o", "p", "q", "r", "s", "t",
  12                                                                                 "u", "v", "w", "x", "y", "z", "1", "2", "3", "4",
  13                                                                                 "5", "6", "7", "8", "9", "0", " "};
  14
  15 const char *ma[] = {"•-", "-•••", "-•-•", "-••", "•", "••-•", "--•",
  16                                                                                 "••••", "••", "•---", "-•-", "•-••", "--", "-•",
  17                                                                                 "---", "•--•", "--•-", "•-•", "•••", "-", "•--",
  18                                                                                 "•••-", "•--", "-••-", "-•--", "--••", "•----",
  19                                                                                 "••---", "•••--", "••••-", "•••••", "-••••",
  20                                                                                 "--•••", "---••", "----•", "-----", " "};
  21
  22 void
  23 convert(char *c)
  24 {
  25         if (strcmp(c, "\n") == 0) {
  26                 printf("\n");
  27                 return;
  28         }
  29
  30         for (int i = 0; aa[i]; i++) {
  31                 if (strcmp(c, aa[i]) == 0) {
  32                         printf("%s", ma[i]);
  33                         break;
  34                 } else if (i == sizeof(aa)/sizeof(char *) - 1) {
  35                         printf("?");
  36                 }
  37         }
  38         printf(" ");
  39 }
  40
  41 int
  42 main(int argc, char **argv)
  43 {
  44         (void)argc;
  45         char c[2];
  46         c[1] = '\0';
  47
  48         if (argv[1] && strcmp(argv[1], "-") != 0) {
  49                 for (int i = 0; argv[1][i]; i++) {
  50                         c[0] = argv[1][i];
  51                         convert(c);
  52                 }
  53         } else {
  54                 while (read(STDIN_FILENO, &c[0], 1) > 0) {
  55                         convert(c);
  56                 }
  57         }
  58         printf("\n");
  59         return 0;
  60 }