examples/validchars/validchr.c

   1 /* by tino@augsburg.net
   2  */
   3
   4 #include <stdio.h>
   5 #include <string.h>
   6
   7 #include <dirent.h>
   8
   9 unsigned char
  10 test(void)
  11 {
  12   DIR           *dir;
  13   struct dirent *dp;
  14   unsigned char c;
  15
  16   if ((dir=opendir("."))==0)
  17     {
  18       perror("open .");
  19       return 0;
  20     }
  21   c     = 0;
  22   while ((dp=readdir(dir))!=0)
  23     {
  24       size_t len;
  25
  26       len       = strlen(dp->d_name);
  27       if (len<4)
  28         continue;
  29       if (strcmp(dp->d_name+len-4, ".TST"))
  30         continue;
  31       if (len!=5)
  32         {
  33           fprintf(stderr, "warning: %s\n", dp->d_name);
  34           printf(" length");
  35           continue;
  36         }
  37       if (c)
  38         printf(" double%d\n", c);
  39       c = dp->d_name[0];
  40     }
  41   if (closedir(dir))
  42     perror("close .");
  43   return c;
  44 }
  45
  46 int
  47 main(void)
  48 {
  49   char          name[256];
  50   unsigned char map[256], upper[256], lower[256];
  51   int           i, j, c;
  52   FILE          *fd;
  53
  54   if (test())
  55     {
  56       printf("There are *.TST files, please remove\n");
  57       return 0;
  58     }
  59   for (i=0; ++i<256; )
  60     {
  61       lower[i]  = i;
  62       upper[i]  = 0;
  63     }
  64   for (i=256; --i; )
  65     {
  66       map[i]    = i;
  67       strcpy(name, "..TST");
  68       name[0]   = i;
  69       printf("%d:", i);
  70       if ((fd=fopen(name, "w"))==0)
  71         printf(" open");
  72       else
  73         fclose(fd);
  74       c = test();
  75       if (unlink(name))
  76         printf(" unlink");
  77       if (c==i)
  78         printf(" ok");
  79       else
  80         printf(" %d", c);
  81       printf("\n");
  82       if (c!=i)
  83         {
  84           upper[c]++;
  85           lower[c]      = i;
  86         }
  87       map[i]    = c;
  88     }
  89
  90   /* Uppercase characters are detected above on:
  91    * The character is mapped to itself and there is a
  92    * character which maps to it.
  93    * Lowercase characters are the lowest character pointing to another one.
  94    * Else it is a one way character.
  95    *
  96    * For this reason we have to process the list
  97    * 1) for 'one way' characters
  98    *    'one way' is something which is no upper and no lower character.
  99    *    This is an awful, crude and ugly hack due to missing Samba support.
 100    * 2) for true uppercase/lowercase characters
 101    * 3) for standalone characters
 102    * Note that there might be characters which do not fall into 1 to 3.
 103    */
 104   printf("\n   valid chars =");
 105   for (i=0; ++i<256; )
 106     if (map[i] && map[i]!=i && lower[map[i]]!=i)
 107       {
 108         if (!upper[i])
 109           printf(" %d:%d %d:%d %d:%d",                                  /*1*/
 110                  map[i], i, i, map[i], map[i], map[i]);
 111         else
 112           fprintf(stderr, "ignoring map %d->%d because of %d->%d\n",
 113                   lower[i], i, i, map[i]);
 114       }
 115   for (i=0; ++i<256; )
 116     if (map[i] && map[i]==i)
 117       if (upper[i])
 118         printf(" %d:%d", lower[i], i);                                  /*2*/
 119       else
 120         printf(" %d", i);                                               /*3*/
 121   printf("\n");
 122   return 0;
 123 }