lib/vsprintf.c

   1 /*
   2  *  linux/lib/vsprintf.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8 /*
   9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10  */
  11
  12 /*
  13  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14  * - changed to provide snprintf and vsnprintf functions
  15  */
  16
  17 #include <stdarg.h>
  18 #include <linux/module.h>
  19 #include <linux/types.h>
  20 #include <linux/string.h>
  21 #include <linux/ctype.h>
  22 #include <linux/kernel.h>
  23
  24 #include <asm/div64.h>
  25
  26 /**
  27  * simple_strtoul - convert a string to an unsigned long
  28  * @cp: The start of the string
  29  * @endp: A pointer to the end of the parsed string will be placed here
  30  * @base: The number base to use
  31  */
  32 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  33 {
  34         unsigned long result = 0,value;
  35
  36         if (!base) {
  37                 base = 10;
  38                 if (*cp == '0') {
  39                         base = 8;
  40                         cp++;
  41                         if ((*cp == 'x') && isxdigit(cp[1])) {
  42                                 cp++;
  43                                 base = 16;
  44                         }
  45                 }
  46         }
  47         while (isxdigit(*cp) &&
  48                (value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) {
  49                 result = result*base + value;
  50                 cp++;
  51         }
  52         if (endp)
  53                 *endp = (char *)cp;
  54         return result;
  55 }
  56
  57 EXPORT_SYMBOL(simple_strtoul);
  58
  59 /**
  60  * simple_strtol - convert a string to a signed long
  61  * @cp: The start of the string
  62  * @endp: A pointer to the end of the parsed string will be placed here
  63  * @base: The number base to use
  64  */
  65 long simple_strtol(const char *cp,char **endp,unsigned int base)
  66 {
  67         if(*cp=='-')
  68                 return -simple_strtoul(cp+1,endp,base);
  69         return simple_strtoul(cp,endp,base);
  70 }
  71
  72 EXPORT_SYMBOL(simple_strtol);
  73
  74 /**
  75  * simple_strtoull - convert a string to an unsigned long long
  76  * @cp: The start of the string
  77  * @endp: A pointer to the end of the parsed string will be placed here
  78  * @base: The number base to use
  79  */
  80 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
  81 {
  82         unsigned long long result = 0,value;
  83
  84         if (!base) {
  85                 base = 10;
  86                 if (*cp == '0') {
  87                         base = 8;
  88                         cp++;
  89                         if ((*cp == 'x') && isxdigit(cp[1])) {
  90                                 cp++;
  91                                 base = 16;
  92                         }
  93                 }
  94         }
  95         while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
  96             ? toupper(*cp) : *cp)-'A'+10) < base) {
  97                 result = result*base + value;
  98                 cp++;
  99         }
 100         if (endp)
 101                 *endp = (char *)cp;
 102         return result;
 103 }
 104
 105 EXPORT_SYMBOL(simple_strtoull);
 106
 107 /**
 108  * simple_strtoll - convert a string to a signed long long
 109  * @cp: The start of the string
 110  * @endp: A pointer to the end of the parsed string will be placed here
 111  * @base: The number base to use
 112  */
 113 long long simple_strtoll(const char *cp,char **endp,unsigned int base)
 114 {
 115         if(*cp=='-')
 116                 return -simple_strtoull(cp+1,endp,base);
 117         return simple_strtoull(cp,endp,base);
 118 }
 119
 120 static int skip_atoi(const char **s)
 121 {
 122         int i=0;
 123
 124         while (isdigit(**s))
 125                 i = i*10 + *((*s)++) - '0';
 126         return i;
 127 }
 128
 129 #define ZEROPAD 1               /* pad with zero */
 130 #define SIGN    2               /* unsigned/signed long */
 131 #define PLUS    4               /* show plus */
 132 #define SPACE   8               /* space if plus */
 133 #define LEFT    16              /* left justified */
 134 #define SPECIAL 32              /* 0x */
 135 #define LARGE   64              /* use 'ABCDEF' instead of 'abcdef' */
 136
 137 static char * number(char * buf, char * end, unsigned long long num, int base, int size, int precision, int type)
 138 {
 139         char c,sign,tmp[66];
 140         const char *digits;
 141         static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
 142         static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 143         int i;
 144
 145         digits = (type & LARGE) ? large_digits : small_digits;
 146         if (type & LEFT)
 147                 type &= ~ZEROPAD;
 148         if (base < 2 || base > 36)
 149                 return 0;
 150         c = (type & ZEROPAD) ? '0' : ' ';
 151         sign = 0;
 152         if (type & SIGN) {
 153                 if ((signed long long) num < 0) {
 154                         sign = '-';
 155                         num = - (signed long long) num;
 156                         size--;
 157                 } else if (type & PLUS) {
 158                         sign = '+';
 159                         size--;
 160                 } else if (type & SPACE) {
 161                         sign = ' ';
 162                         size--;
 163                 }
 164         }
 165         if (type & SPECIAL) {
 166                 if (base == 16)
 167                         size -= 2;
 168                 else if (base == 8)
 169                         size--;
 170         }
 171         i = 0;
 172         if (num == 0)
 173                 tmp[i++]='0';
 174         else while (num != 0)
 175                 tmp[i++] = digits[do_div(num,base)];
 176         if (i > precision)
 177                 precision = i;
 178         size -= precision;
 179         if (!(type&(ZEROPAD+LEFT))) {
 180                 while(size-->0) {
 181                         if (buf <= end)
 182                                 *buf = ' ';
 183                         ++buf;
 184                 }
 185         }
 186         if (sign) {
 187                 if (buf <= end)
 188                         *buf = sign;
 189                 ++buf;
 190         }
 191         if (type & SPECIAL) {
 192                 if (base==8) {
 193                         if (buf <= end)
 194                                 *buf = '0';
 195                         ++buf;
 196                 } else if (base==16) {
 197                         if (buf <= end)
 198                                 *buf = '0';
 199                         ++buf;
 200                         if (buf <= end)
 201                                 *buf = digits[33];
 202                         ++buf;
 203                 }
 204         }
 205         if (!(type & LEFT)) {
 206                 while (size-- > 0) {
 207                         if (buf <= end)
 208                                 *buf = c;
 209                         ++buf;
 210                 }
 211         }
 212         while (i < precision--) {
 213                 if (buf <= end)
 214                         *buf = '0';
 215                 ++buf;
 216         }
 217         while (i-- > 0) {
 218                 if (buf <= end)
 219                         *buf = tmp[i];
 220                 ++buf;
 221         }
 222         while (size-- > 0) {
 223                 if (buf <= end)
 224                         *buf = ' ';
 225                 ++buf;
 226         }
 227         return buf;
 228 }
 229
 230 /**
 231 * vsnprintf - Format a string and place it in a buffer
 232 * @buf: The buffer to place the result into
 233 * @size: The size of the buffer, including the trailing null space
 234 * @fmt: The format string to use
 235 * @args: Arguments for the format string
 236 *
 237 * Call this function if you are already dealing with a va_list.
 238 * You probably want snprintf instead.
 239  */
 240 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 241 {
 242         int len;
 243         unsigned long long num;
 244         int i, base;
 245         char *str, *end, c;
 246         const char *s;
 247
 248         int flags;              /* flags to number() */
 249
 250         int field_width;        /* width of output field */
 251         int precision;          /* min. # of digits for integers; max
 252                                    number of chars for from string */
 253         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 254                                 /* 'z' support added 23/7/1999 S.H.    */
 255                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 256
 257         str = buf;
 258         end = buf + size - 1;
 259
 260         if (end < buf - 1) {
 261                 end = ((void *) -1);
 262                 size = end - buf + 1;
 263         }
 264
 265         for (; *fmt ; ++fmt) {
 266                 if (*fmt != '%') {
 267                         if (str <= end)
 268                                 *str = *fmt;
 269                         ++str;
 270                         continue;
 271                 }
 272
 273                 /* process flags */
 274                 flags = 0;
 275                 repeat:
 276                         ++fmt;          /* this also skips first '%' */
 277                         switch (*fmt) {
 278                                 case '-': flags |= LEFT; goto repeat;
 279                                 case '+': flags |= PLUS; goto repeat;
 280                                 case ' ': flags |= SPACE; goto repeat;
 281                                 case '#': flags |= SPECIAL; goto repeat;
 282                                 case '0': flags |= ZEROPAD; goto repeat;
 283                         }
 284
 285                 /* get field width */
 286                 field_width = -1;
 287                 if (isdigit(*fmt))
 288                         field_width = skip_atoi(&fmt);
 289                 else if (*fmt == '*') {
 290                         ++fmt;
 291                         /* it's the next argument */
 292                         field_width = va_arg(args, int);
 293                         if (field_width < 0) {
 294                                 field_width = -field_width;
 295                                 flags |= LEFT;
 296                         }
 297                 }
 298
 299                 /* get the precision */
 300                 precision = -1;
 301                 if (*fmt == '.') {
 302                         ++fmt;
 303                         if (isdigit(*fmt))
 304                                 precision = skip_atoi(&fmt);
 305                         else if (*fmt == '*') {
 306                                 ++fmt;
 307                                 /* it's the next argument */
 308                                 precision = va_arg(args, int);
 309                         }
 310                         if (precision < 0)
 311                                 precision = 0;
 312                 }
 313
 314                 /* get the conversion qualifier */
 315                 qualifier = -1;
 316                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 317                     *fmt =='Z' || *fmt == 'z') {
 318                         qualifier = *fmt;
 319                         ++fmt;
 320                         if (qualifier == 'l' && *fmt == 'l') {
 321                                 qualifier = 'L';
 322                                 ++fmt;
 323                         }
 324                 }
 325
 326                 /* default base */
 327                 base = 10;
 328
 329                 switch (*fmt) {
 330                         case 'c':
 331                                 if (!(flags & LEFT)) {
 332                                         while (--field_width > 0) {
 333                                                 if (str <= end)
 334                                                         *str = ' ';
 335                                                 ++str;
 336                                         }
 337                                 }
 338                                 c = (unsigned char) va_arg(args, int);
 339                                 if (str <= end)
 340                                         *str = c;
 341                                 ++str;
 342                                 while (--field_width > 0) {
 343                                         if (str <= end)
 344                                                 *str = ' ';
 345                                         ++str;
 346                                 }
 347                                 continue;
 348
 349                         case 's':
 350                                 s = va_arg(args, char *);
 351                                 if ((unsigned long)s < PAGE_SIZE)
 352                                         s = "<NULL>";
 353
 354                                 len = strnlen(s, precision);
 355
 356                                 if (!(flags & LEFT)) {
 357                                         while (len < field_width--) {
 358                                                 if (str <= end)
 359                                                         *str = ' ';
 360                                                 ++str;
 361                                         }
 362                                 }
 363                                 for (i = 0; i < len; ++i) {
 364                                         if (str <= end)
 365                                                 *str = *s;
 366                                         ++str; ++s;
 367                                 }
 368                                 while (len < field_width--) {
 369                                         if (str <= end)
 370                                                 *str = ' ';
 371                                         ++str;
 372                                 }
 373                                 continue;
 374
 375                         case 'p':
 376                                 if (field_width == -1) {
 377                                         field_width = 2*sizeof(void *);
 378                                         flags |= ZEROPAD;
 379                                 }
 380                                 str = number(str, end,
 381                                                 (unsigned long) va_arg(args, void *),
 382                                                 16, field_width, precision, flags);
 383                                 continue;
 384
 385
 386                         case 'n':
 387                                 /* FIXME:
 388                                 * What does C99 say about the overflow case here? */
 389                                 if (qualifier == 'l') {
 390                                         long * ip = va_arg(args, long *);
 391                                         *ip = (str - buf);
 392                                 } else if (qualifier == 'Z' || qualifier == 'z') {
 393                                         size_t * ip = va_arg(args, size_t *);
 394                                         *ip = (str - buf);
 395                                 } else {
 396                                         int * ip = va_arg(args, int *);
 397                                         *ip = (str - buf);
 398                                 }
 399                                 continue;
 400
 401                         case '%':
 402                                 if (str <= end)
 403                                         *str = '%';
 404                                 ++str;
 405                                 continue;
 406
 407                                 /* integer number formats - set up the flags and "break" */
 408                         case 'o':
 409                                 base = 8;
 410                                 break;
 411
 412                         case 'X':
 413                                 flags |= LARGE;
 414                         case 'x':
 415                                 base = 16;
 416                                 break;
 417
 418                         case 'd':
 419                         case 'i':
 420                                 flags |= SIGN;
 421                         case 'u':
 422                                 break;
 423
 424                         default:
 425                                 if (str <= end)
 426                                         *str = '%';
 427                                 ++str;
 428                                 if (*fmt) {
 429                                         if (str <= end)
 430                                                 *str = *fmt;
 431                                         ++str;
 432                                 } else {
 433                                         --fmt;
 434                                 }
 435                                 continue;
 436                 }
 437                 if (qualifier == 'L')
 438                         num = va_arg(args, long long);
 439                 else if (qualifier == 'l') {
 440                         num = va_arg(args, unsigned long);
 441                         if (flags & SIGN)
 442                                 num = (signed long) num;
 443                 } else if (qualifier == 'Z' || qualifier == 'z') {
 444                         num = va_arg(args, size_t);
 445                 } else if (qualifier == 'h') {
 446                         num = (unsigned short) va_arg(args, int);
 447                         if (flags & SIGN)
 448                                 num = (signed short) num;
 449                 } else {
 450                         num = va_arg(args, unsigned int);
 451                         if (flags & SIGN)
 452                                 num = (signed int) num;
 453                 }
 454                 str = number(str, end, num, base,
 455                                 field_width, precision, flags);
 456         }
 457         if (str <= end)
 458                 *str = '\0';
 459         else if (size > 0)
 460                 /* don't write out a null byte if the buf size is zero */
 461                 *end = '\0';
 462         /* the trailing null byte doesn't count towards the total
 463         * ++str;
 464         */
 465         return str-buf;
 466 }
 467
 468 EXPORT_SYMBOL(vsnprintf);
 469
 470 /**
 471  * snprintf - Format a string and place it in a buffer
 472  * @buf: The buffer to place the result into
 473  * @size: The size of the buffer, including the trailing null space
 474  * @fmt: The format string to use
 475  * @...: Arguments for the format string
 476  */
 477 int snprintf(char * buf, size_t size, const char *fmt, ...)
 478 {
 479         va_list args;
 480         int i;
 481
 482         va_start(args, fmt);
 483         i=vsnprintf(buf,size,fmt,args);
 484         va_end(args);
 485         return i;
 486 }
 487
 488 EXPORT_SYMBOL(snprintf);
 489
 490 /**
 491  * vsprintf - Format a string and place it in a buffer
 492  * @buf: The buffer to place the result into
 493  * @fmt: The format string to use
 494  * @args: Arguments for the format string
 495  *
 496  * Call this function if you are already dealing with a va_list.
 497  * You probably want sprintf instead.
 498  */
 499 int vsprintf(char *buf, const char *fmt, va_list args)
 500 {
 501         return vsnprintf(buf, 0xFFFFFFFFUL, fmt, args);
 502 }
 503
 504 EXPORT_SYMBOL(vsprintf);
 505
 506 /**
 507  * sprintf - Format a string and place it in a buffer
 508  * @buf: The buffer to place the result into
 509  * @fmt: The format string to use
 510  * @...: Arguments for the format string
 511  */
 512 int sprintf(char * buf, const char *fmt, ...)
 513 {
 514         va_list args;
 515         int i;
 516
 517         va_start(args, fmt);
 518         i=vsprintf(buf,fmt,args);
 519         va_end(args);
 520         return i;
 521 }
 522
 523 EXPORT_SYMBOL(sprintf);
 524
 525 /**
 526  * vsscanf - Unformat a buffer into a list of arguments
 527  * @buf:        input buffer
 528  * @fmt:        format of buffer
 529  * @args:       arguments
 530  */
 531 int vsscanf(const char * buf, const char * fmt, va_list args)
 532 {
 533         const char *str = buf;
 534         char *next;
 535         char digit;
 536         int num = 0;
 537         int qualifier;
 538         int base;
 539         int field_width;
 540         int is_sign = 0;
 541
 542         while(*fmt && *str) {
 543                 /* skip any white space in format */
 544                 /* white space in format matchs any amount of
 545                  * white space, including none, in the input.
 546                  */
 547                 if (isspace(*fmt)) {
 548                         while (isspace(*fmt))
 549                                 ++fmt;
 550                         while (isspace(*str))
 551                                 ++str;
 552                 }
 553
 554                 /* anything that is not a conversion must match exactly */
 555                 if (*fmt != '%' && *fmt) {
 556                         if (*fmt++ != *str++)
 557                                 break;
 558                         continue;
 559                 }
 560
 561                 if (!*fmt)
 562                         break;
 563                 ++fmt;
 564
 565                 /* skip this conversion.
 566                  * advance both strings to next white space
 567                  */
 568                 if (*fmt == '*') {
 569                         while (!isspace(*fmt) && *fmt)
 570                                 fmt++;
 571                         while (!isspace(*str) && *str)
 572                                 str++;
 573                         continue;
 574                 }
 575
 576                 /* get field width */
 577                 field_width = -1;
 578                 if (isdigit(*fmt))
 579                         field_width = skip_atoi(&fmt);
 580
 581                 /* get conversion qualifier */
 582                 qualifier = -1;
 583                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 584                     *fmt == 'Z' || *fmt == 'z') {
 585                         qualifier = *fmt;
 586                         fmt++;
 587                 }
 588                 base = 10;
 589                 is_sign = 0;
 590
 591                 if (!*fmt || !*str)
 592                         break;
 593
 594                 switch(*fmt++) {
 595                 case 'c':
 596                 {
 597                         char *s = (char *) va_arg(args,char*);
 598                         if (field_width == -1)
 599                                 field_width = 1;
 600                         do {
 601                                 *s++ = *str++;
 602                         } while(field_width-- > 0 && *str);
 603                         num++;
 604                 }
 605                 continue;
 606                 case 's':
 607                 {
 608                         char *s = (char *) va_arg(args, char *);
 609                         if(field_width == -1)
 610                                 field_width = INT_MAX;
 611                         /* first, skip leading white space in buffer */
 612                         while (isspace(*str))
 613                                 str++;
 614
 615                         /* now copy until next white space */
 616                         while (*str && !isspace(*str) && field_width--) {
 617                                 *s++ = *str++;
 618                         }
 619                         *s = '\0';
 620                         num++;
 621                 }
 622                 continue;
 623                 case 'n':
 624                         /* return number of characters read so far */
 625                 {
 626                         int *i = (int *)va_arg(args,int*);
 627                         *i = str - buf;
 628                 }
 629                 continue;
 630                 case 'o':
 631                         base = 8;
 632                         break;
 633                 case 'x':
 634                 case 'X':
 635                         base = 16;
 636                         break;
 637                 case 'i':
 638                         base = 0;
 639                 case 'd':
 640                         is_sign = 1;
 641                 case 'u':
 642                         break;
 643                 case '%':
 644                         /* looking for '%' in str */
 645                         if (*str++ != '%')
 646                                 return num;
 647                         continue;
 648                 default:
 649                         /* invalid format; stop here */
 650                         return num;
 651                 }
 652
 653                 /* have some sort of integer conversion.
 654                  * first, skip white space in buffer.
 655                  */
 656                 while (isspace(*str))
 657                         str++;
 658
 659                 digit = *str;
 660                 if (is_sign && digit == '-')
 661                         digit = *(str + 1);
 662
 663                 if (!digit
 664                     || (base == 16 && !isxdigit(digit))
 665                     || (base == 10 && !isdigit(digit))
 666                     || (base == 8 && (!isdigit(digit) || digit > '7'))
 667                     || (base == 0 && !isdigit(digit)))
 668                                 break;
 669
 670                 switch(qualifier) {
 671                 case 'h':
 672                         if (is_sign) {
 673                                 short *s = (short *) va_arg(args,short *);
 674                                 *s = (short) simple_strtol(str,&next,base);
 675                         } else {
 676                                 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
 677                                 *s = (unsigned short) simple_strtoul(str, &next, base);
 678                         }
 679                         break;
 680                 case 'l':
 681                         if (is_sign) {
 682                                 long *l = (long *) va_arg(args,long *);
 683                                 *l = simple_strtol(str,&next,base);
 684                         } else {
 685                                 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
 686                                 *l = simple_strtoul(str,&next,base);
 687                         }
 688                         break;
 689                 case 'L':
 690                         if (is_sign) {
 691                                 long long *l = (long long*) va_arg(args,long long *);
 692                                 *l = simple_strtoll(str,&next,base);
 693                         } else {
 694                                 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
 695                                 *l = simple_strtoull(str,&next,base);
 696                         }
 697                         break;
 698                 case 'Z':
 699                 case 'z':
 700                 {
 701                         size_t *s = (size_t*) va_arg(args,size_t*);
 702                         *s = (size_t) simple_strtoul(str,&next,base);
 703                 }
 704                 break;
 705                 default:
 706                         if (is_sign) {
 707                                 int *i = (int *) va_arg(args, int*);
 708                                 *i = (int) simple_strtol(str,&next,base);
 709                         } else {
 710                                 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
 711                                 *i = (unsigned int) simple_strtoul(str,&next,base);
 712                         }
 713                         break;
 714                 }
 715                 num++;
 716
 717                 if (!next)
 718                         break;
 719                 str = next;
 720         }
 721         return num;
 722 }
 723
 724 EXPORT_SYMBOL(vsscanf);
 725
 726 /**
 727  * sscanf - Unformat a buffer into a list of arguments
 728  * @buf:        input buffer
 729  * @fmt:        formatting of buffer
 730  * @...:        resulting arguments
 731  */
 732 int sscanf(const char * buf, const char * fmt, ...)
 733 {
 734         va_list args;
 735         int i;
 736
 737         va_start(args,fmt);
 738         i = vsscanf(buf,fmt,args);
 739         va_end(args);
 740         return i;
 741 }
 742
 743 EXPORT_SYMBOL(sscanf);