Usermode/Libraries/libc.so_src/scanf.c

   1 /*
   2  * Acess2 C Library
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * scanf.c
   6  * - *scanf family of functions
   7  */
   8 #include <stdio.h>
   9 #include <stdarg.h>
  10 #include <ctype.h>
  11 #include <string.h>
  12
  13 extern void     _SysDebug(const char *format, ...);
  14
  15 enum e_vcscanf_types
  16 {
  17         _VCSCANF_NOTYPE,
  18         _VCSCANF_INT,
  19         _VCSCANF_REAL,
  20 };
  21
  22 enum e_vcscanf_sizes
  23 {
  24         _VCSCANF_UNDEF,
  25         _VCSCANF_CHAR,
  26         _VCSCANF_SHORT,
  27         _VCSCANF_LONG,
  28         _VCSCANF_LONGLONG,
  29         _VCSCANF_INTMAX,
  30         _VCSCANF_SIZET,
  31         _VCSCANF_PTRDIFF,
  32         _VCSCANF_LONGDOUBLE
  33 };
  34
  35 // === CODE ===
  36 int _vcscanf_int(int (*__getc)(void *), void (*__rewind)(void*), void *h, int base, int maxlen, long long *outval)
  37 {
  38         char    ich;
  39          int    sgn = 1;
  40         long long int   ret = 0;
  41          int    n_read = 0;
  42
  43         // Initialise output to something sane
  44         *outval = 0;
  45
  46         // First character
  47         // - maxlen == 0 means no limit
  48         ich = __getc(h);
  49         n_read ++;
  50
  51         // Sign?
  52         if( ich == '-' || ich == '+' ) {
  53                 sgn = (ich == '-' ? -1 : 1);
  54                 if( n_read == maxlen )
  55                         return n_read;
  56                 ich = __getc(h);
  57                 n_read ++;
  58         }
  59
  60         // Determine base
  61         if( base == 0 ) {
  62                 if( ich != '0' ) {
  63                         base = 10;
  64                 }
  65                 else {
  66                         if( n_read == maxlen )
  67                                 return n_read;
  68                         ich = __getc(h);
  69                         n_read ++;
  70                         if( ich != 'x' ) {
  71                                 base = 8;
  72                         }
  73                         else {
  74                                 base = 16;
  75                                 if( n_read == maxlen )
  76                                         return n_read;
  77                                 ich = __getc(h);
  78                                 n_read ++;
  79                         }
  80                 }
  81         }
  82
  83         if( ich == 0 ) {
  84                 // Oops?
  85                 return n_read;
  86         }
  87
  88         while( ich )
  89         {
  90                  int    next = -1;
  91
  92                 // Get the digit value
  93                 if( base <= 10 ) {
  94                         if( '0' <= ich && ich <= '0'+base-1 )
  95                                 next = ich - '0';
  96                 }
  97                 else {
  98                         if( '0' <= ich && ich <= '9' )
  99                                 next = ich - '0';
 100                         if( 'A' <= ich && ich <= 'A'+base-10-1 )
 101                                 next = ich - 'A' + 10;
 102                         if( 'a' <= ich && ich <= 'a'+base-10-1 )
 103                                 next = ich - 'a' + 10;
 104                 }
 105                 // if it's not a digit, rewind and break
 106                 if( next < 0 ) {
 107                         __rewind(h);
 108                         n_read --;
 109                         break;
 110                 }
 111
 112                 // Add to the result
 113                 ret *= base;
 114                 ret += next;
 115                 //_SysDebug("- %i/%i read, 0x%x val", n_read, maxlen, ret);
 116
 117                 // Check if we've reached the limit
 118                 if( n_read == maxlen )
 119                         break ;
 120
 121                 // Next character
 122                 ich = __getc(h);
 123                 n_read ++;
 124         }
 125
 126         // Apply sign
 127         if( sgn == -1 )
 128                 ret = -ret;
 129
 130         *outval = ret;
 131         return n_read;
 132 }
 133
 134 int _vcscanf(int (*__getc)(void*), void (*__rewind)(void*), void *h, const char *format, va_list ap)
 135 {
 136         char    fch, ich;
 137          int    ret = 0, nch = 0;
 138
 139         while( (fch = *format++) )
 140         {
 141                 union {
 142                         void    *_void;
 143                         char    *_char;
 144                         short   *_short;
 145                          int    *_int;
 146                         long    *_long;
 147                         long long       *_longlong;
 148                 }       ptr;
 149                 long long       ival;
 150                 //long double   rval;
 151                  int    maxlen = 0;
 152                 // int  offset = -1;
 153                 enum e_vcscanf_sizes    size = _VCSCANF_UNDEF;
 154                 enum e_vcscanf_types    valtype;
 155                  int    fail = 0;
 156                  int    nnewch;
 157
 158                 const char      *set_start;
 159                  int    set_len;
 160
 161                 // Whitespace matches any ammount of whitespace (including none)
 162                 if( isspace(fch) )
 163                 {
 164                         while( (ich = __getc(h)) && isspace(ich) )
 165                                 nch ++;
 166                         if(ich) __rewind(h);
 167                         continue ;
 168                 }
 169
 170                 // Any non-whitespace and non-% characters must match exactly
 171                 if( fch != '%' )
 172                 {
 173                         if( __getc(h) != fch )
 174                                 break;
 175                         nch ++;
 176                         continue ;
 177                 }
 178
 179                 // Format specifier
 180                 fch = *format++;
 181                 if(!fch)        break;
 182
 183                 // Catch '%%' early
 184                 if( fch == '%' ) {
 185                         if( __getc(h) != '%' )
 186                                 break;
 187                         nch ++;
 188                         continue ;
 189                 }
 190
 191                 // %n$ - Direct offset selection, shouldn't be mixed with just %
 192                 #if 0
 193                 for( ; isdigit(fch); fch = *format++ )
 194                         maxlen = maxlen * 10 + (fch - '0');
 195                 if( fch == '$' ) {
 196                         offset = maxlen;
 197                         maxlen = 0;
 198                 }
 199                 #endif
 200
 201                 // Supress assignemnt?
 202                 if( fch == '*' )
 203                 {
 204                         fch = *format++;
 205                         ptr._void = NULL;
 206                         ret --;
 207                 }
 208                 else
 209                         ptr._void = va_arg(ap, void*);
 210
 211                 // Max field length
 212                 while( isdigit(fch) )
 213                 {
 214                         maxlen = maxlen * 10 + fch - '0';
 215                         fch = *format++;
 216                 }
 217
 218                 // Length modifier
 219                 switch( fch )
 220                 {
 221                 case 'h':
 222                         // 'short'
 223                         size = _VCSCANF_SHORT;
 224                         fch = *format++;
 225                         if( fch == 'h' ) {
 226                                 // 'char'
 227                                 size = _VCSCANF_CHAR;
 228                                 fch = *format++;
 229                         }
 230                         break;
 231                 case 'l':
 232                         // 'long'
 233                         size = _VCSCANF_LONG;
 234                         fch = *format++;
 235                         if( fch == 'l' ) {
 236                                 // 'long long'
 237                                 size = _VCSCANF_LONGLONG;
 238                                 fch = *format++;
 239                         }
 240                         break;
 241                 case 'j':
 242                         // '(u)intmax_t'
 243                         size = _VCSCANF_INTMAX;
 244                         fch = *format++;
 245                         break;
 246                 case 'z':
 247                         // 'size_t'
 248                         size = _VCSCANF_SIZET;
 249                         fch = *format++;
 250                         break;
 251                 case 't':
 252                         // 'ptrdiff_t'
 253                         size = _VCSCANF_PTRDIFF;
 254                         fch = *format++;
 255                         break;
 256                 case 'L':
 257                         // 'long double' (a, A, e, E, f, F, g, G)
 258                         size = _VCSCANF_LONGDOUBLE;
 259                         fch = *format++;
 260                         break;
 261                 }
 262
 263                 // Format specifiers
 264                 switch( fch )
 265                 {
 266                 // Decimal integer
 267                 case 'd':
 268                         nnewch = _vcscanf_int(__getc, __rewind, h, 10, maxlen, &ival);
 269                         if(nnewch==0)   fail=1;
 270                         nch += nnewch;
 271                         valtype = _VCSCANF_INT;
 272                         break;
 273                 // variable-base integer
 274                 case 'i':
 275                         nnewch = _vcscanf_int(__getc, __rewind, h, 0, maxlen, &ival);
 276                         if(nnewch==0)   fail=1;
 277                         nch += nnewch;
 278                         valtype = _VCSCANF_INT;
 279                         break;
 280                 // Octal integer
 281                 case 'o':
 282                         nnewch = _vcscanf_int(__getc, __rewind, h, 8, maxlen, &ival);
 283                         if(nnewch==0)   fail=1;
 284                         nch += nnewch;
 285                         valtype = _VCSCANF_INT;
 286                         break;
 287                 // Hexadecimal integer
 288                 case 'x': case 'X':
 289                         nnewch = _vcscanf_int(__getc, __rewind, h, 16, maxlen, &ival);
 290                         if(nnewch==0)   fail=1;
 291                         nch += nnewch;
 292                         valtype = _VCSCANF_INT;
 293                         break;
 294                 // strtod format float
 295                 case 'a': case 'A':
 296                 case 'e': case 'E':
 297                 case 'f': case 'F':
 298                 case 'g': case 'G':
 299                         valtype = _VCSCANF_REAL;
 300                         break;
 301                 // `maxlen` or 1 characters
 302                 case 'c':
 303                         if( maxlen == 0 )
 304                                 maxlen = 1;
 305                         while( maxlen -- && (ich = __getc(h)) )
 306                         {
 307                                 if(ptr._char)   *ptr._char++ = ich;
 308                                 nch ++;
 309                         }
 310                         valtype = _VCSCANF_NOTYPE;
 311                         break;
 312                 // sequence of non-whitespace characters
 313                 case 's':
 314                         if( maxlen == 0 )
 315                                 maxlen = -1;
 316
 317                         ich = 0;
 318                         while( maxlen -- && (ich = __getc(h)) && !isspace(ich) )
 319                         {
 320                                 if(ptr._char)   *ptr._char++ = ich;
 321                                 nch ++;
 322                         }
 323                         if( maxlen >= 0 && ich )
 324                                 __rewind(h);
 325                         if(ptr._char)   *ptr._char++ = 0;
 326                         valtype = _VCSCANF_NOTYPE;
 327                         break;
 328                 // match a set of characters
 329                 case '[': {
 330                         int invert = 0;
 331                         if( *format++ == '^' ) {
 332                                 // Invert
 333                                 invert = 1;
 334                         }
 335                         set_start = format;
 336                         set_len = 0;
 337                         // if the first character is ']' it's part of the set
 338                         do {
 339                                 // permissable character
 340                                 set_len ++;
 341                                 fch = *format++;
 342                         } while( fch && fch != ']' );
 343
 344                         if( maxlen == 0 )
 345                                 maxlen = -1;
 346                         ich = 0;
 347                         while( maxlen -- && (ich = __getc(h)) && invert == !memchr(set_start, set_len, ich) )
 348                         {
 349                                 if(ptr._char)   *ptr._char++ = ich;
 350                                 nch ++;
 351                         }
 352                         if( maxlen >= 0 && ich )
 353                                 __rewind(h);
 354                         if(ptr._char)   *ptr._char++ = 0;
 355                         valtype = _VCSCANF_NOTYPE;
 356                         break;
 357                         }
 358                 case 'p': // read back printf("%p")
 359                         valtype = _VCSCANF_NOTYPE;
 360                         break;
 361                 case 'n': // number of read characters to this point
 362                         if(ptr._int) {
 363                                 *ptr._int = nch;
 364                                 ret --; // negates the ret ++ at the end
 365                         }
 366                         valtype = _VCSCANF_NOTYPE;
 367                         break;
 368                 default:
 369                         // Implimentation defined
 370                         valtype = _VCSCANF_NOTYPE;
 371                         break;
 372                 }
 373
 374                 if(fail)
 375                         break;
 376
 377                 switch(valtype)
 378                 {
 379                 case _VCSCANF_NOTYPE:
 380                         // Used when assignment is done above
 381                         break;
 382                 case _VCSCANF_INT:
 383                         switch(size)
 384                         {
 385                         case _VCSCANF_UNDEF:    *ptr._int = ival;       break;
 386                         case _VCSCANF_CHAR:     *ptr._char = ival;      break;
 387                         case _VCSCANF_SHORT:    *ptr._short = ival;     break;
 388                         case _VCSCANF_LONG:     *ptr._long = ival;      break;
 389                         case _VCSCANF_LONGLONG: *ptr._longlong = ival;  break;
 390                         default:        // ???
 391                                 break;
 392                         }
 393                         break;
 394                 case _VCSCANF_REAL:
 395                         break;
 396                 }
 397
 398                 ret ++;
 399         }
 400
 401         return ret;
 402 }
 403
 404 int _vsscanf_getc(void *h)
 405 {
 406         const char      **ibuf = h;
 407         return *(*ibuf)++;      // Dereference, read for return, increment
 408 }
 409
 410 void _vsscanf_rewind(void *h)
 411 {
 412         const char      **ibuf = h;
 413         (*ibuf) --;     // NOTE: Breaks if there's a rewind before a getc, but that shouldn't happen
 414 }
 415
 416 int vscanf(const char *format, va_list ap)
 417 {
 418         return vfscanf(stdin, format, ap);
 419 }
 420
 421 int vsscanf(const char *str, const char *format, va_list ap)
 422 {
 423         return _vcscanf(_vsscanf_getc, _vsscanf_rewind, &str, format, ap);
 424 }
 425
 426 int _vfscanf_getc(void *h)
 427 {
 428         int ch = fgetc(h);
 429         return ch == -1 ? 0 : ch;
 430 }
 431 void _vfscanf_rewind(void *h)
 432 {
 433         fseek(h, -1, SEEK_CUR);
 434 }
 435
 436 int vfscanf(FILE *stream, const char *format, va_list ap)
 437 {
 438         return _vcscanf(_vfscanf_getc, _vfscanf_rewind, stream, format, ap);
 439 }
 440
 441 int scanf(const char *format, ...)
 442 {
 443         va_list args;
 444          int    rv;
 445         va_start(args, format);
 446         rv = vfscanf(stdin, format, args);
 447         va_end(args);
 448         return rv;
 449 }
 450 int fscanf(FILE *stream, const char *format, ...)
 451 {
 452         va_list args;
 453          int    rv;
 454         va_start(args, format);
 455         rv = vfscanf(stream, format, args);
 456         va_end(args);
 457         return rv;
 458 }
 459 int sscanf(const char *str, const char *format, ...)
 460 {
 461         va_list args;
 462          int    rv;
 463         va_start(args, format);
 464         rv = vsscanf(str, format, args);
 465         va_end(args);
 466         return rv;
 467 }
 468