#include "defs"
s243(pd0)                   /*  2.4.3 Character constants  */
struct defs *pd0;
{
   static char s243er[] = "s243,er%d\n";
   static char qs243[8] = "s243   ";
   char *ps, *pt;
   int rc;
   char chars[256];

   rc = 0;
   ps = qs243;
   pt = pd0->rfs;
   while(*pt++ = *ps++);

     /* One of the problems that arises when testing character constants
        is that of definition: What, exactly, is the character set?
        In order to guarantee a certain amount of machine independence,
        the character set we will use here is the set of characters writ-
        able as escape sequences in C, plus those characters used in writ-
        ing C programs, i.e.,

        letters:
                   ABCDEFGHIJKLMNOPQRSTUVWXYZ      26
                   abcdefghijklmnopqrstuvwxyz      26
        numbers:
                   0123456789                      10
        special characters:
                   ~!"#%&()_=-^|{}[]+;*:<>,.?/     27
        extra special characters:
		   alert	     \a
                   newline           \n       
                   horizontal tab    \t
		   vertical tab	     \v
                   backspace         \b
                   carriage return   \r
                   form feed         \f
                   backslash         \\
                   single quote      \'             9
        blank & NUL                                 2
                                                  ---
                                                  100

        Any specific implementation of C may of course support additional
        characters.                                       */

        /* Since the value of a character constant is the numerical value
           of the character in the machine's character set, there should
           be a one-to-one correspondence between characters and values. */

   zerofill(chars);

   chars['a'] = 1;   chars['A'] = 1;   chars['~'] = 1;   chars['0'] = 1;
   chars['b'] = 1;   chars['B'] = 1;   chars['!'] = 1;   chars['1'] = 1;
   chars['c'] = 1;   chars['C'] = 1;   chars['"'] = 1;   chars['2'] = 1;
   chars['d'] = 1;   chars['D'] = 1;   chars['#'] = 1;   chars['3'] = 1;
   chars['e'] = 1;   chars['E'] = 1;   chars['%'] = 1;   chars['4'] = 1;
   chars['f'] = 1;   chars['F'] = 1;   chars['&'] = 1;   chars['5'] = 1;
   chars['g'] = 1;   chars['G'] = 1;   chars['('] = 1;   chars['6'] = 1;
   chars['h'] = 1;   chars['H'] = 1;   chars[')'] = 1;   chars['7'] = 1;
   chars['i'] = 1;   chars['I'] = 1;   chars['_'] = 1;   chars['8'] = 1;
   chars['j'] = 1;   chars['J'] = 1;   chars['='] = 1;   chars['9'] = 1;
   chars['k'] = 1;   chars['K'] = 1;   chars['-'] = 1;   chars['\v'] = 1;
   chars['l'] = 1;   chars['L'] = 1;   chars['^'] = 1;   chars['\a'] = 1;
   chars['m'] = 1;   chars['M'] = 1;   chars['|'] = 1;   chars['\n'] = 1;
   chars['n'] = 1;   chars['N'] = 1;                     chars['\t'] = 1;
   chars['o'] = 1;   chars['O'] = 1;   chars['{'] = 1;   chars['\b'] = 1;
   chars['p'] = 1;   chars['P'] = 1;   chars['}'] = 1;   chars['\r'] = 1;
   chars['q'] = 1;   chars['Q'] = 1;   chars['['] = 1;   chars['\f'] = 1;
   chars['r'] = 1;   chars['R'] = 1;   chars[']'] = 1;   chars['\\'] = 1;
   chars['s'] = 1;   chars['S'] = 1;   chars['+'] = 1;   chars['\''] = 1;
   chars['t'] = 1;   chars['T'] = 1;   chars[';'] = 1;   
   chars['u'] = 1;   chars['U'] = 1;   chars['*'] = 1;  
   chars['v'] = 1;   chars['V'] = 1;   chars[':'] = 1;   chars['\0'] = 1;
   chars['w'] = 1;   chars['W'] = 1;   chars['<'] = 1;   chars[' '] = 1;
   chars['x'] = 1;   chars['X'] = 1;   chars['>'] = 1;
   chars['y'] = 1;   chars['Y'] = 1;   chars[','] = 1;
   chars['z'] = 1;   chars['Z'] = 1;   chars['.'] = 1;
                                       chars['?'] = 1;
                                       chars['/'] = 1;

   if(sumof(chars) != 100){
     rc = rc+1;
     if(pd0->flgd != 0) printf(s243er,1);
   }

   /* If the character following a backslash is not one of those
      specified, the backslash is ignored.           */

		     chars['\A'] = 0;  chars['\~'] = 0;     
		     chars['\B'] = 0;  chars['\!'] = 0;  
   chars['\c'] = 0;  chars['\C'] = 0;  chars['\"'] = 0;  
   chars['\d'] = 0;  chars['\D'] = 0;  chars['\#'] = 0;  
   chars['\e'] = 0;  chars['\E'] = 0;  chars['\%'] = 0;  
                     chars['\F'] = 0;  chars['\&'] = 0;  
   chars['\g'] = 0;  chars['\G'] = 0;  chars['\('] = 0;  
   chars['\h'] = 0;  chars['\H'] = 0;  chars['\)'] = 0;  
   chars['\i'] = 0;  chars['\I'] = 0;  chars['\_'] = 0;  
   chars['\j'] = 0;  chars['\J'] = 0;  chars['\='] = 0;  
   chars['\k'] = 0;  chars['\K'] = 0;  chars['\-'] = 0;
   chars['\l'] = 0;  chars['\L'] = 0;  chars['\^'] = 0;
   chars['\m'] = 0;  chars['\M'] = 0;  chars['\|'] = 0;  
                     chars['\N'] = 0;        
   chars['\o'] = 0;  chars['\O'] = 0;  chars['\{'] = 0;  
   chars['\p'] = 0;  chars['\P'] = 0;  chars['\}'] = 0;  
   chars['\q'] = 0;  chars['\Q'] = 0;  chars['\['] = 0;  
                     chars['\R'] = 0;  chars['\]'] = 0;  
   chars['\s'] = 0;  chars['\S'] = 0;  chars['\+'] = 0;  
                     chars['\T'] = 0;  chars['\;'] = 0;  
   chars['\u'] = 0;  chars['\U'] = 0;  chars['\*'] = 0; 
		     chars['\V'] = 0;  chars['\:'] = 0;  
   chars['\w'] = 0;  chars['\W'] = 0;  chars['\<'] = 0;  chars['\ '] = 0;
		     chars['\X'] = 0;  chars['\>'] = 0;
   chars['\y'] = 0;  chars['\Y'] = 0;  chars['\,'] = 0;
   chars['\z'] = 0;  chars['\Z'] = 0;  chars['\.'] = 0;
                                       chars['\?'] = 0;
                                       chars['\/'] = 0;

   if(anyof(chars,"avxntbrf0\a\v\n\t\b\r\f\\\'\0",19) == 0){
     rc = rc+2;
     if(pd0->flgd != 0) printf(s243er,2);
   }
   if(sumof(chars) != 28) {
     rc = rc+4;
     if(pd0->flgd != 0) printf(s243er,4);
   }

   /* Finally, the escape \ddd consists of the backslash followed
      by 1, 2, or 3 octal digits which are taken to specify  the
      desired character.                           */

   if( '\0'    !=   0 || '\01'   !=   1 || '\02'   !=   2
    || '\03'   !=   3 || '\04'   !=   4 || '\05'   !=   5
    || '\06'   !=   6 || '\07'   !=   7 || '\10'   !=   8
    || '\17'   !=  15 || '\20'   !=  16 || '\77'   !=  63
    || '\100'  !=  64 || '\177'  != 127                 ){
   
     rc = rc+8;
     if(pd0->flgd != 0) printf(s243er,8);
   }

   return rc;
}
zerofill(x)
char *x;
{
   int j;

   for (j=0; j<256; j++) *x++ = 0;
}
sumof(x)
char *x;
{
   char *p;
   int total, j;

   p = x;
   total = 0;

   for(j=0; j<256; j++) total = total+ *p++;
   return total;
}
anyof(x,s,n)
char *s, *x;
int n;
{
   int j, val;

   val = 1;

   for(j=0; j<n; j++) val = val*(*(x+(*(s+j))));

   return val;
}