ascii.c

   1 /* depend: */
   2 /* cflags: */
   3 /* linker: */
   4
   5 #include <assert.h>
   6 #include <getopt.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <unistd.h>
  10
  11 /* macros */
  12
  13 #define VERBOSE(level, statement...) do { if (level <= verbose) { statement; } } while(0)
  14
  15 /* gobal variables */
  16
  17 char *progname = NULL;
  18 int verbose = 0;
  19 int nbcols = 4;
  20
  21 char tablechars[256][4] = {
  22     "NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "DEL",
  23     "DS",  "HT",  "LF",  "VT",  "FF",  "CR",  "SO",  "SI",
  24     "DLE", "DC1", "DC2", "DC3", "DC4", "NAK", "SYN", "ETB",
  25     "CAN", "EM",  "SUB", "ESC", "FS",  "GS",  "RS",  "US",
  26     "SP",  "",    "",    "",    "",    "",    "",    "",
  27     "",    "",    "",    "",    "",    "",    "",    "",
  28     "",    "",    "",    "",    "",    "",    "",    "",
  29     "",    "",    "",    "",    "",    "",    "",    "",
  30     "",    "",    "",    "",    "",    "",    "",    "",
  31     "",    "",    "",    "",    "",    "",    "",    "",
  32     "",    "",    "",    "",    "",    "",    "",    "",
  33     "",    "",    "",    "",    "",    "",    "",    "",
  34     "",    "",    "",    "",    "",    "",    "",    "",
  35     "",    "",    "",    "",    "",    "",    "",    "",
  36     "",    "",    "",    "",    "",    "",    "",    "",
  37     "",    "",    "",    "",    "",    "",    "",    "DEL"};
  38
  39 /* help function */
  40
  41 void usage (int ret)
  42 {
  43     FILE *fd = ret ? stderr : stdout;
  44     fprintf (fd, "usage: %s\n", progname);
  45     fprintf (fd, " -c : number of columns (%d)\n", nbcols);
  46     fprintf (fd, " -h : help message\n");
  47     fprintf (fd, " -v : verbose level (%d)\n", verbose);
  48
  49     exit (ret);
  50 }
  51
  52 /* main function */
  53
  54 int main (int argc, char *argv[])
  55 {
  56     int i;
  57
  58     progname = argv[0];
  59
  60     int c;
  61     while ((c = getopt(argc, argv, "c:hv:")) != EOF) {
  62         switch (c) {
  63         case 'c':
  64             nbcols = atoi (optarg);
  65             break;
  66         case 'v':
  67             verbose = atoi (optarg);
  68             break;
  69         case 'h':
  70         default:
  71             usage (c != 'h');
  72         }
  73     }
  74     if (argc - optind != 0) {
  75         fprintf (stderr, "%s: invalid option -- %s\n", progname, argv[optind]);
  76         usage (1);
  77     }
  78
  79     for (i = 0; i < 256; i++) {
  80         char line[] = "   :  :    x";
  81
  82         if (i > 99) line[0] = '0' + i / 100;
  83         if (i > 9) line[1] = '0' + (i / 10) % 10;
  84         line[2] = '0' + i % 10;
  85         line[4] = '0' + i / 16;
  86         if (line[4] > '9') line[4] += 'a' - '0' - 10;
  87         line[5] = '0' + i % 16;
  88         if (line[5] > '9') line[5] += 'a' - '0' - 10;
  89
  90         if (tablechars[i][0] != '\0') {
  91             int j = 0;
  92             while (tablechars[i][j] != '\0') {
  93                 line[8 + j] = tablechars[i][j];
  94                 j++;
  95             }
  96         } else {
  97             line[8] = i;
  98         }
  99         line[11] = (((i + 1) % nbcols == 0) || (i == 255)) ? '\n' : ' ';
 100
 101         write (STDOUT_FILENO, line, 12);
 102     }
 103
 104     return 0;
 105 }
 106
 107 // test: ascii.exe -h
 108 // test: ascii.exe -h | awk '/usage:/ { rc=1 } END { exit (1-rc) }'
 109 // test: ascii.exe -_ 2> /dev/null | awk 'END { if (NR == 0) { exit(0) } else exit (1) }'
 110 // test: ascii.exe -_ 2>&1 | awk '/usage:/ { rc=1 } END { exit (1-rc) }'
 111
 112 /* vim: set ts=4 sw=4 et: */