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  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  16  * - scnprintf and vscnprintf
  17  */
  18
  19 #include <stdarg.h>
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/ctype.h>
  24 #include <linux/kernel.h>
  25
  26 #include <asm/page.h>           /* for PAGE_SIZE */
  27 #include <asm/div64.h>
  28
  29 /**
  30  * simple_strtoul - convert a string to an unsigned long
  31  * @cp: The start of the string
  32  * @endp: A pointer to the end of the parsed string will be placed here
  33  * @base: The number base to use
  34  */
  35 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  36 {
  37         unsigned long result = 0,value;
  38
  39         if (!base) {
  40                 base = 10;
  41                 if (*cp == '0') {
  42                         base = 8;
  43                         cp++;
  44                         if ((toupper(*cp) == 'X') && isxdigit(cp[1])) {
  45                                 cp++;
  46                                 base = 16;
  47                         }
  48                 }
  49         } else if (base == 16) {
  50                 if (cp[0] == '0' && toupper(cp[1]) == 'X')
  51                         cp += 2;
  52         }
  53         while (isxdigit(*cp) &&
  54                (value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) {
  55                 result = result*base + value;
  56                 cp++;
  57         }
  58         if (endp)
  59                 *endp = (char *)cp;
  60         return result;
  61 }
  62
  63 EXPORT_SYMBOL(simple_strtoul);
  64
  65 /**
  66  * simple_strtol - convert a string to a signed long
  67  * @cp: The start of the string
  68  * @endp: A pointer to the end of the parsed string will be placed here
  69  * @base: The number base to use
  70  */
  71 long simple_strtol(const char *cp,char **endp,unsigned int base)
  72 {
  73         if(*cp=='-')
  74                 return -simple_strtoul(cp+1,endp,base);
  75         return simple_strtoul(cp,endp,base);
  76 }
  77
  78 EXPORT_SYMBOL(simple_strtol);
  79
  80 /**
  81  * simple_strtoull - convert a string to an unsigned long long
  82  * @cp: The start of the string
  83  * @endp: A pointer to the end of the parsed string will be placed here
  84  * @base: The number base to use
  85  */
  86 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
  87 {
  88         unsigned long long result = 0,value;
  89
  90         if (!base) {
  91                 base = 10;
  92                 if (*cp == '0') {
  93                         base = 8;
  94                         cp++;
  95                         if ((toupper(*cp) == 'X') && isxdigit(cp[1])) {
  96                                 cp++;
  97                                 base = 16;
  98                         }
  99                 }
 100         } else if (base == 16) {
 101                 if (cp[0] == '0' && toupper(cp[1]) == 'X')
 102                         cp += 2;
 103         }
 104         while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
 105             ? toupper(*cp) : *cp)-'A'+10) < base) {
 106                 result = result*base + value;
 107                 cp++;
 108         }
 109         if (endp)
 110                 *endp = (char *)cp;
 111         return result;
 112 }
 113
 114 EXPORT_SYMBOL(simple_strtoull);
 115
 116 /**
 117  * simple_strtoll - convert a string to a signed long long
 118  * @cp: The start of the string
 119  * @endp: A pointer to the end of the parsed string will be placed here
 120  * @base: The number base to use
 121  */
 122 long long simple_strtoll(const char *cp,char **endp,unsigned int base)
 123 {
 124         if(*cp=='-')
 125                 return -simple_strtoull(cp+1,endp,base);
 126         return simple_strtoull(cp,endp,base);
 127 }
 128
 129
 130 /**
 131  * strict_strtoul - convert a string to an unsigned long strictly
 132  * @cp: The string to be converted
 133  * @base: The number base to use
 134  * @res: The converted result value
 135  *
 136  * strict_strtoul converts a string to an unsigned long only if the
 137  * string is really an unsigned long string, any string containing
 138  * any invalid char at the tail will be rejected and -EINVAL is returned,
 139  * only a newline char at the tail is acceptible because people generally
 140  * change a module parameter in the following way:
 141  *
 142  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 143  *
 144  * echo will append a newline to the tail.
 145  *
 146  * It returns 0 if conversion is successful and *res is set to the converted
 147  * value, otherwise it returns -EINVAL and *res is set to 0.
 148  *
 149  * simple_strtoul just ignores the successive invalid characters and
 150  * return the converted value of prefix part of the string.
 151  */
 152 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
 153
 154 /**
 155  * strict_strtol - convert a string to a long strictly
 156  * @cp: The string to be converted
 157  * @base: The number base to use
 158  * @res: The converted result value
 159  *
 160  * strict_strtol is similiar to strict_strtoul, but it allows the first
 161  * character of a string is '-'.
 162  *
 163  * It returns 0 if conversion is successful and *res is set to the converted
 164  * value, otherwise it returns -EINVAL and *res is set to 0.
 165  */
 166 int strict_strtol(const char *cp, unsigned int base, long *res);
 167
 168 /**
 169  * strict_strtoull - convert a string to an unsigned long long strictly
 170  * @cp: The string to be converted
 171  * @base: The number base to use
 172  * @res: The converted result value
 173  *
 174  * strict_strtoull converts a string to an unsigned long long only if the
 175  * string is really an unsigned long long string, any string containing
 176  * any invalid char at the tail will be rejected and -EINVAL is returned,
 177  * only a newline char at the tail is acceptible because people generally
 178  * change a module parameter in the following way:
 179  *
 180  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 181  *
 182  * echo will append a newline to the tail of the string.
 183  *
 184  * It returns 0 if conversion is successful and *res is set to the converted
 185  * value, otherwise it returns -EINVAL and *res is set to 0.
 186  *
 187  * simple_strtoull just ignores the successive invalid characters and
 188  * return the converted value of prefix part of the string.
 189  */
 190 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);
 191
 192 /**
 193  * strict_strtoll - convert a string to a long long strictly
 194  * @cp: The string to be converted
 195  * @base: The number base to use
 196  * @res: The converted result value
 197  *
 198  * strict_strtoll is similiar to strict_strtoull, but it allows the first
 199  * character of a string is '-'.
 200  *
 201  * It returns 0 if conversion is successful and *res is set to the converted
 202  * value, otherwise it returns -EINVAL and *res is set to 0.
 203  */
 204 int strict_strtoll(const char *cp, unsigned int base, long long *res);
 205
 206 #define define_strict_strtoux(type, valtype)                            \
 207 int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\
 208 {                                                                       \
 209         char *tail;                                                     \
 210         valtype val;                                                    \
 211         size_t len;                                                     \
 212                                                                         \
 213         *res = 0;                                                       \
 214         len = strlen(cp);                                               \
 215         if (len == 0)                                                   \
 216                 return -EINVAL;                                         \
 217                                                                         \
 218         val = simple_strtoul(cp, &tail, base);                          \
 219         if ((*tail == '\0') ||                                          \
 220                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {\
 221                 *res = val;                                             \
 222                 return 0;                                               \
 223         }                                                               \
 224                                                                         \
 225         return -EINVAL;                                                 \
 226 }                                                                       \
 227
 228 #define define_strict_strtox(type, valtype)                             \
 229 int strict_strto##type(const char *cp, unsigned int base, valtype *res) \
 230 {                                                                       \
 231         int ret;                                                        \
 232         if (*cp == '-') {                                               \
 233                 ret = strict_strtou##type(cp+1, base, res);             \
 234                 if (ret != 0)                                           \
 235                         *res = -(*res);                                 \
 236         } else                                                          \
 237                 ret = strict_strtou##type(cp, base, res);               \
 238                                                                         \
 239         return ret;                                                     \
 240 }                                                                       \
 241
 242 define_strict_strtoux(l, unsigned long)
 243 define_strict_strtox(l, long)
 244 define_strict_strtoux(ll, unsigned long long)
 245 define_strict_strtox(ll, long long)
 246
 247 EXPORT_SYMBOL(strict_strtoul);
 248 EXPORT_SYMBOL(strict_strtol);
 249 EXPORT_SYMBOL(strict_strtoll);
 250 EXPORT_SYMBOL(strict_strtoull);
 251
 252 static int skip_atoi(const char **s)
 253 {
 254         int i=0;
 255
 256         while (isdigit(**s))
 257                 i = i*10 + *((*s)++) - '0';
 258         return i;
 259 }
 260
 261 /* Decimal conversion is by far the most typical, and is used
 262  * for /proc and /sys data. This directly impacts e.g. top performance
 263  * with many processes running. We optimize it for speed
 264  * using code from
 265  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 266  * (with permission from the author, Douglas W. Jones). */
 267
 268 /* Formats correctly any integer in [0,99999].
 269  * Outputs from one to five digits depending on input.
 270  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 271 static char* put_dec_trunc(char *buf, unsigned q)
 272 {
 273         unsigned d3, d2, d1, d0;
 274         d1 = (q>>4) & 0xf;
 275         d2 = (q>>8) & 0xf;
 276         d3 = (q>>12);
 277
 278         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 279         q = (d0 * 0xcd) >> 11;
 280         d0 = d0 - 10*q;
 281         *buf++ = d0 + '0'; /* least significant digit */
 282         d1 = q + 9*d3 + 5*d2 + d1;
 283         if (d1 != 0) {
 284                 q = (d1 * 0xcd) >> 11;
 285                 d1 = d1 - 10*q;
 286                 *buf++ = d1 + '0'; /* next digit */
 287
 288                 d2 = q + 2*d2;
 289                 if ((d2 != 0) || (d3 != 0)) {
 290                         q = (d2 * 0xd) >> 7;
 291                         d2 = d2 - 10*q;
 292                         *buf++ = d2 + '0'; /* next digit */
 293
 294                         d3 = q + 4*d3;
 295                         if (d3 != 0) {
 296                                 q = (d3 * 0xcd) >> 11;
 297                                 d3 = d3 - 10*q;
 298                                 *buf++ = d3 + '0';  /* next digit */
 299                                 if (q != 0)
 300                                         *buf++ = q + '0';  /* most sign. digit */
 301                         }
 302                 }
 303         }
 304         return buf;
 305 }
 306 /* Same with if's removed. Always emits five digits */
 307 static char* put_dec_full(char *buf, unsigned q)
 308 {
 309         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 310         /* but anyway, gcc produces better code with full-sized ints */
 311         unsigned d3, d2, d1, d0;
 312         d1 = (q>>4) & 0xf;
 313         d2 = (q>>8) & 0xf;
 314         d3 = (q>>12);
 315
 316         /* Possible ways to approx. divide by 10 */
 317         /* gcc -O2 replaces multiply with shifts and adds */
 318         // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 319         // (x * 0x67) >> 10:  1100111
 320         // (x * 0x34) >> 9:    110100 - same
 321         // (x * 0x1a) >> 8:     11010 - same
 322         // (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 323
 324         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 325         q = (d0 * 0xcd) >> 11;
 326         d0 = d0 - 10*q;
 327         *buf++ = d0 + '0';
 328         d1 = q + 9*d3 + 5*d2 + d1;
 329                 q = (d1 * 0xcd) >> 11;
 330                 d1 = d1 - 10*q;
 331                 *buf++ = d1 + '0';
 332
 333                 d2 = q + 2*d2;
 334                         q = (d2 * 0xd) >> 7;
 335                         d2 = d2 - 10*q;
 336                         *buf++ = d2 + '0';
 337
 338                         d3 = q + 4*d3;
 339                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 340                                 /* q = (d3 * 0x67) >> 10; - would also work */
 341                                 d3 = d3 - 10*q;
 342                                 *buf++ = d3 + '0';
 343                                         *buf++ = q + '0';
 344         return buf;
 345 }
 346 /* No inlining helps gcc to use registers better */
 347 static noinline char* put_dec(char *buf, unsigned long long num)
 348 {
 349         while (1) {
 350                 unsigned rem;
 351                 if (num < 100000)
 352                         return put_dec_trunc(buf, num);
 353                 rem = do_div(num, 100000);
 354                 buf = put_dec_full(buf, rem);
 355         }
 356 }
 357
 358 #define ZEROPAD 1               /* pad with zero */
 359 #define SIGN    2               /* unsigned/signed long */
 360 #define PLUS    4               /* show plus */
 361 #define SPACE   8               /* space if plus */
 362 #define LEFT    16              /* left justified */
 363 #define SPECIAL 32              /* 0x */
 364 #define LARGE   64              /* use 'ABCDEF' instead of 'abcdef' */
 365
 366 static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
 367 {
 368         char sign,tmp[66];
 369         const char *digits;
 370         /* we are called with base 8, 10 or 16, only, thus don't need "g..."  */
 371         static const char small_digits[] = "0123456789abcdefx"; /* "ghijklmnopqrstuvwxyz"; */
 372         static const char large_digits[] = "0123456789ABCDEFX"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 373         int need_pfx = ((type & SPECIAL) && base != 10);
 374         int i;
 375
 376         digits = (type & LARGE) ? large_digits : small_digits;
 377         if (type & LEFT)
 378                 type &= ~ZEROPAD;
 379         if (base < 2 || base > 36)
 380                 return NULL;
 381         sign = 0;
 382         if (type & SIGN) {
 383                 if ((signed long long) num < 0) {
 384                         sign = '-';
 385                         num = - (signed long long) num;
 386                         size--;
 387                 } else if (type & PLUS) {
 388                         sign = '+';
 389                         size--;
 390                 } else if (type & SPACE) {
 391                         sign = ' ';
 392                         size--;
 393                 }
 394         }
 395         if (need_pfx) {
 396                 size--;
 397                 if (base == 16)
 398                         size--;
 399         }
 400
 401         /* generate full string in tmp[], in reverse order */
 402         i = 0;
 403         if (num == 0)
 404                 tmp[i++] = '0';
 405         /* Generic code, for any base:
 406         else do {
 407                 tmp[i++] = digits[do_div(num,base)];
 408         } while (num != 0);
 409         */
 410         else if (base != 10) { /* 8 or 16 */
 411                 int mask = base - 1;
 412                 int shift = 3;
 413                 if (base == 16) shift = 4;
 414                 do {
 415                         tmp[i++] = digits[((unsigned char)num) & mask];
 416                         num >>= shift;
 417                 } while (num);
 418         } else { /* base 10 */
 419                 i = put_dec(tmp, num) - tmp;
 420         }
 421
 422         /* printing 100 using %2d gives "100", not "00" */
 423         if (i > precision)
 424                 precision = i;
 425         /* leading space padding */
 426         size -= precision;
 427         if (!(type & (ZEROPAD+LEFT))) {
 428                 while(--size >= 0) {
 429                         if (buf < end)
 430                                 *buf = ' ';
 431                         ++buf;
 432                 }
 433         }
 434         /* sign */
 435         if (sign) {
 436                 if (buf < end)
 437                         *buf = sign;
 438                 ++buf;
 439         }
 440         /* "0x" / "0" prefix */
 441         if (need_pfx) {
 442                 if (buf < end)
 443                         *buf = '0';
 444                 ++buf;
 445                 if (base == 16) {
 446                         if (buf < end)
 447                                 *buf = digits[16]; /* for arbitrary base: digits[33]; */
 448                         ++buf;
 449                 }
 450         }
 451         /* zero or space padding */
 452         if (!(type & LEFT)) {
 453                 char c = (type & ZEROPAD) ? '0' : ' ';
 454                 while (--size >= 0) {
 455                         if (buf < end)
 456                                 *buf = c;
 457                         ++buf;
 458                 }
 459         }
 460         /* hmm even more zero padding? */
 461         while (i <= --precision) {
 462                 if (buf < end)
 463                         *buf = '0';
 464                 ++buf;
 465         }
 466         /* actual digits of result */
 467         while (--i >= 0) {
 468                 if (buf < end)
 469                         *buf = tmp[i];
 470                 ++buf;
 471         }
 472         /* trailing space padding */
 473         while (--size >= 0) {
 474                 if (buf < end)
 475                         *buf = ' ';
 476                 ++buf;
 477         }
 478         return buf;
 479 }
 480
 481 /**
 482  * vsnprintf - Format a string and place it in a buffer
 483  * @buf: The buffer to place the result into
 484  * @size: The size of the buffer, including the trailing null space
 485  * @fmt: The format string to use
 486  * @args: Arguments for the format string
 487  *
 488  * The return value is the number of characters which would
 489  * be generated for the given input, excluding the trailing
 490  * '\0', as per ISO C99. If you want to have the exact
 491  * number of characters written into @buf as return value
 492  * (not including the trailing '\0'), use vscnprintf(). If the
 493  * return is greater than or equal to @size, the resulting
 494  * string is truncated.
 495  *
 496  * Call this function if you are already dealing with a va_list.
 497  * You probably want snprintf() instead.
 498  */
 499 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 500 {
 501         int len;
 502         unsigned long long num;
 503         int i, base;
 504         char *str, *end, c;
 505         const char *s;
 506
 507         int flags;              /* flags to number() */
 508
 509         int field_width;        /* width of output field */
 510         int precision;          /* min. # of digits for integers; max
 511                                    number of chars for from string */
 512         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 513                                 /* 'z' support added 23/7/1999 S.H.    */
 514                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 515                                 /* 't' added for ptrdiff_t */
 516
 517         /* Reject out-of-range values early.  Large positive sizes are
 518            used for unknown buffer sizes. */
 519         if (unlikely((int) size < 0)) {
 520                 /* There can be only one.. */
 521                 static char warn = 1;
 522                 WARN_ON(warn);
 523                 warn = 0;
 524                 return 0;
 525         }
 526
 527         str = buf;
 528         end = buf + size;
 529
 530         /* Make sure end is always >= buf */
 531         if (end < buf) {
 532                 end = ((void *)-1);
 533                 size = end - buf;
 534         }
 535
 536         for (; *fmt ; ++fmt) {
 537                 if (*fmt != '%') {
 538                         if (str < end)
 539                                 *str = *fmt;
 540                         ++str;
 541                         continue;
 542                 }
 543
 544                 /* process flags */
 545                 flags = 0;
 546                 repeat:
 547                         ++fmt;          /* this also skips first '%' */
 548                         switch (*fmt) {
 549                                 case '-': flags |= LEFT; goto repeat;
 550                                 case '+': flags |= PLUS; goto repeat;
 551                                 case ' ': flags |= SPACE; goto repeat;
 552                                 case '#': flags |= SPECIAL; goto repeat;
 553                                 case '0': flags |= ZEROPAD; goto repeat;
 554                         }
 555
 556                 /* get field width */
 557                 field_width = -1;
 558                 if (isdigit(*fmt))
 559                         field_width = skip_atoi(&fmt);
 560                 else if (*fmt == '*') {
 561                         ++fmt;
 562                         /* it's the next argument */
 563                         field_width = va_arg(args, int);
 564                         if (field_width < 0) {
 565                                 field_width = -field_width;
 566                                 flags |= LEFT;
 567                         }
 568                 }
 569
 570                 /* get the precision */
 571                 precision = -1;
 572                 if (*fmt == '.') {
 573                         ++fmt;
 574                         if (isdigit(*fmt))
 575                                 precision = skip_atoi(&fmt);
 576                         else if (*fmt == '*') {
 577                                 ++fmt;
 578                                 /* it's the next argument */
 579                                 precision = va_arg(args, int);
 580                         }
 581                         if (precision < 0)
 582                                 precision = 0;
 583                 }
 584
 585                 /* get the conversion qualifier */
 586                 qualifier = -1;
 587                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 588                     *fmt =='Z' || *fmt == 'z' || *fmt == 't') {
 589                         qualifier = *fmt;
 590                         ++fmt;
 591                         if (qualifier == 'l' && *fmt == 'l') {
 592                                 qualifier = 'L';
 593                                 ++fmt;
 594                         }
 595                 }
 596
 597                 /* default base */
 598                 base = 10;
 599
 600                 switch (*fmt) {
 601                         case 'c':
 602                                 if (!(flags & LEFT)) {
 603                                         while (--field_width > 0) {
 604                                                 if (str < end)
 605                                                         *str = ' ';
 606                                                 ++str;
 607                                         }
 608                                 }
 609                                 c = (unsigned char) va_arg(args, int);
 610                                 if (str < end)
 611                                         *str = c;
 612                                 ++str;
 613                                 while (--field_width > 0) {
 614                                         if (str < end)
 615                                                 *str = ' ';
 616                                         ++str;
 617                                 }
 618                                 continue;
 619
 620                         case 's':
 621                                 s = va_arg(args, char *);
 622                                 if ((unsigned long)s < PAGE_SIZE)
 623                                         s = "<NULL>";
 624
 625                                 len = strnlen(s, precision);
 626
 627                                 if (!(flags & LEFT)) {
 628                                         while (len < field_width--) {
 629                                                 if (str < end)
 630                                                         *str = ' ';
 631                                                 ++str;
 632                                         }
 633                                 }
 634                                 for (i = 0; i < len; ++i) {
 635                                         if (str < end)
 636                                                 *str = *s;
 637                                         ++str; ++s;
 638                                 }
 639                                 while (len < field_width--) {
 640                                         if (str < end)
 641                                                 *str = ' ';
 642                                         ++str;
 643                                 }
 644                                 continue;
 645
 646                         case 'p':
 647                                 if (field_width == -1) {
 648                                         field_width = 2*sizeof(void *);
 649                                         flags |= ZEROPAD;
 650                                 }
 651                                 str = number(str, end,
 652                                                 (unsigned long) va_arg(args, void *),
 653                                                 16, field_width, precision, flags);
 654                                 continue;
 655
 656
 657                         case 'n':
 658                                 /* FIXME:
 659                                 * What does C99 say about the overflow case here? */
 660                                 if (qualifier == 'l') {
 661                                         long * ip = va_arg(args, long *);
 662                                         *ip = (str - buf);
 663                                 } else if (qualifier == 'Z' || qualifier == 'z') {
 664                                         size_t * ip = va_arg(args, size_t *);
 665                                         *ip = (str - buf);
 666                                 } else {
 667                                         int * ip = va_arg(args, int *);
 668                                         *ip = (str - buf);
 669                                 }
 670                                 continue;
 671
 672                         case '%':
 673                                 if (str < end)
 674                                         *str = '%';
 675                                 ++str;
 676                                 continue;
 677
 678                                 /* integer number formats - set up the flags and "break" */
 679                         case 'o':
 680                                 base = 8;
 681                                 break;
 682
 683                         case 'X':
 684                                 flags |= LARGE;
 685                         case 'x':
 686                                 base = 16;
 687                                 break;
 688
 689                         case 'd':
 690                         case 'i':
 691                                 flags |= SIGN;
 692                         case 'u':
 693                                 break;
 694
 695                         default:
 696                                 if (str < end)
 697                                         *str = '%';
 698                                 ++str;
 699                                 if (*fmt) {
 700                                         if (str < end)
 701                                                 *str = *fmt;
 702                                         ++str;
 703                                 } else {
 704                                         --fmt;
 705                                 }
 706                                 continue;
 707                 }
 708                 if (qualifier == 'L')
 709                         num = va_arg(args, long long);
 710                 else if (qualifier == 'l') {
 711                         num = va_arg(args, unsigned long);
 712                         if (flags & SIGN)
 713                                 num = (signed long) num;
 714                 } else if (qualifier == 'Z' || qualifier == 'z') {
 715                         num = va_arg(args, size_t);
 716                 } else if (qualifier == 't') {
 717                         num = va_arg(args, ptrdiff_t);
 718                 } else if (qualifier == 'h') {
 719                         num = (unsigned short) va_arg(args, int);
 720                         if (flags & SIGN)
 721                                 num = (signed short) num;
 722                 } else {
 723                         num = va_arg(args, unsigned int);
 724                         if (flags & SIGN)
 725                                 num = (signed int) num;
 726                 }
 727                 str = number(str, end, num, base,
 728                                 field_width, precision, flags);
 729         }
 730         if (size > 0) {
 731                 if (str < end)
 732                         *str = '\0';
 733                 else
 734                         end[-1] = '\0';
 735         }
 736         /* the trailing null byte doesn't count towards the total */
 737         return str-buf;
 738 }
 739
 740 EXPORT_SYMBOL(vsnprintf);
 741
 742 /**
 743  * vscnprintf - Format a string and place it in a buffer
 744  * @buf: The buffer to place the result into
 745  * @size: The size of the buffer, including the trailing null space
 746  * @fmt: The format string to use
 747  * @args: Arguments for the format string
 748  *
 749  * The return value is the number of characters which have been written into
 750  * the @buf not including the trailing '\0'. If @size is <= 0 the function
 751  * returns 0.
 752  *
 753  * Call this function if you are already dealing with a va_list.
 754  * You probably want scnprintf() instead.
 755  */
 756 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 757 {
 758         int i;
 759
 760         i=vsnprintf(buf,size,fmt,args);
 761         return (i >= size) ? (size - 1) : i;
 762 }
 763
 764 EXPORT_SYMBOL(vscnprintf);
 765
 766 /**
 767  * snprintf - Format a string and place it in a buffer
 768  * @buf: The buffer to place the result into
 769  * @size: The size of the buffer, including the trailing null space
 770  * @fmt: The format string to use
 771  * @...: Arguments for the format string
 772  *
 773  * The return value is the number of characters which would be
 774  * generated for the given input, excluding the trailing null,
 775  * as per ISO C99.  If the return is greater than or equal to
 776  * @size, the resulting string is truncated.
 777  */
 778 int snprintf(char * buf, size_t size, const char *fmt, ...)
 779 {
 780         va_list args;
 781         int i;
 782
 783         va_start(args, fmt);
 784         i=vsnprintf(buf,size,fmt,args);
 785         va_end(args);
 786         return i;
 787 }
 788
 789 EXPORT_SYMBOL(snprintf);
 790
 791 /**
 792  * scnprintf - Format a string and place it in a buffer
 793  * @buf: The buffer to place the result into
 794  * @size: The size of the buffer, including the trailing null space
 795  * @fmt: The format string to use
 796  * @...: Arguments for the format string
 797  *
 798  * The return value is the number of characters written into @buf not including
 799  * the trailing '\0'. If @size is <= 0 the function returns 0.
 800  */
 801
 802 int scnprintf(char * buf, size_t size, const char *fmt, ...)
 803 {
 804         va_list args;
 805         int i;
 806
 807         va_start(args, fmt);
 808         i = vsnprintf(buf, size, fmt, args);
 809         va_end(args);
 810         return (i >= size) ? (size - 1) : i;
 811 }
 812 EXPORT_SYMBOL(scnprintf);
 813
 814 /**
 815  * vsprintf - Format a string and place it in a buffer
 816  * @buf: The buffer to place the result into
 817  * @fmt: The format string to use
 818  * @args: Arguments for the format string
 819  *
 820  * The function returns the number of characters written
 821  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
 822  * buffer overflows.
 823  *
 824  * Call this function if you are already dealing with a va_list.
 825  * You probably want sprintf() instead.
 826  */
 827 int vsprintf(char *buf, const char *fmt, va_list args)
 828 {
 829         return vsnprintf(buf, INT_MAX, fmt, args);
 830 }
 831
 832 EXPORT_SYMBOL(vsprintf);
 833
 834 /**
 835  * sprintf - Format a string and place it in a buffer
 836  * @buf: The buffer to place the result into
 837  * @fmt: The format string to use
 838  * @...: Arguments for the format string
 839  *
 840  * The function returns the number of characters written
 841  * into @buf. Use snprintf() or scnprintf() in order to avoid
 842  * buffer overflows.
 843  */
 844 int sprintf(char * buf, const char *fmt, ...)
 845 {
 846         va_list args;
 847         int i;
 848
 849         va_start(args, fmt);
 850         i=vsnprintf(buf, INT_MAX, fmt, args);
 851         va_end(args);
 852         return i;
 853 }
 854
 855 EXPORT_SYMBOL(sprintf);
 856
 857 /**
 858  * vsscanf - Unformat a buffer into a list of arguments
 859  * @buf:        input buffer
 860  * @fmt:        format of buffer
 861  * @args:       arguments
 862  */
 863 int vsscanf(const char * buf, const char * fmt, va_list args)
 864 {
 865         const char *str = buf;
 866         char *next;
 867         char digit;
 868         int num = 0;
 869         int qualifier;
 870         int base;
 871         int field_width;
 872         int is_sign = 0;
 873
 874         while(*fmt && *str) {
 875                 /* skip any white space in format */
 876                 /* white space in format matchs any amount of
 877                  * white space, including none, in the input.
 878                  */
 879                 if (isspace(*fmt)) {
 880                         while (isspace(*fmt))
 881                                 ++fmt;
 882                         while (isspace(*str))
 883                                 ++str;
 884                 }
 885
 886                 /* anything that is not a conversion must match exactly */
 887                 if (*fmt != '%' && *fmt) {
 888                         if (*fmt++ != *str++)
 889                                 break;
 890                         continue;
 891                 }
 892
 893                 if (!*fmt)
 894                         break;
 895                 ++fmt;
 896
 897                 /* skip this conversion.
 898                  * advance both strings to next white space
 899                  */
 900                 if (*fmt == '*') {
 901                         while (!isspace(*fmt) && *fmt)
 902                                 fmt++;
 903                         while (!isspace(*str) && *str)
 904                                 str++;
 905                         continue;
 906                 }
 907
 908                 /* get field width */
 909                 field_width = -1;
 910                 if (isdigit(*fmt))
 911                         field_width = skip_atoi(&fmt);
 912
 913                 /* get conversion qualifier */
 914                 qualifier = -1;
 915                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 916                     *fmt == 'Z' || *fmt == 'z') {
 917                         qualifier = *fmt++;
 918                         if (unlikely(qualifier == *fmt)) {
 919                                 if (qualifier == 'h') {
 920                                         qualifier = 'H';
 921                                         fmt++;
 922                                 } else if (qualifier == 'l') {
 923                                         qualifier = 'L';
 924                                         fmt++;
 925                                 }
 926                         }
 927                 }
 928                 base = 10;
 929                 is_sign = 0;
 930
 931                 if (!*fmt || !*str)
 932                         break;
 933
 934                 switch(*fmt++) {
 935                 case 'c':
 936                 {
 937                         char *s = (char *) va_arg(args,char*);
 938                         if (field_width == -1)
 939                                 field_width = 1;
 940                         do {
 941                                 *s++ = *str++;
 942                         } while (--field_width > 0 && *str);
 943                         num++;
 944                 }
 945                 continue;
 946                 case 's':
 947                 {
 948                         char *s = (char *) va_arg(args, char *);
 949                         if(field_width == -1)
 950                                 field_width = INT_MAX;
 951                         /* first, skip leading white space in buffer */
 952                         while (isspace(*str))
 953                                 str++;
 954
 955                         /* now copy until next white space */
 956                         while (*str && !isspace(*str) && field_width--) {
 957                                 *s++ = *str++;
 958                         }
 959                         *s = '\0';
 960                         num++;
 961                 }
 962                 continue;
 963                 case 'n':
 964                         /* return number of characters read so far */
 965                 {
 966                         int *i = (int *)va_arg(args,int*);
 967                         *i = str - buf;
 968                 }
 969                 continue;
 970                 case 'o':
 971                         base = 8;
 972                         break;
 973                 case 'x':
 974                 case 'X':
 975                         base = 16;
 976                         break;
 977                 case 'i':
 978                         base = 0;
 979                 case 'd':
 980                         is_sign = 1;
 981                 case 'u':
 982                         break;
 983                 case '%':
 984                         /* looking for '%' in str */
 985                         if (*str++ != '%')
 986                                 return num;
 987                         continue;
 988                 default:
 989                         /* invalid format; stop here */
 990                         return num;
 991                 }
 992
 993                 /* have some sort of integer conversion.
 994                  * first, skip white space in buffer.
 995                  */
 996                 while (isspace(*str))
 997                         str++;
 998
 999                 digit = *str;
1000                 if (is_sign && digit == '-')
1001                         digit = *(str + 1);
1002
1003                 if (!digit
1004                     || (base == 16 && !isxdigit(digit))
1005                     || (base == 10 && !isdigit(digit))
1006                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1007                     || (base == 0 && !isdigit(digit)))
1008                                 break;
1009
1010                 switch(qualifier) {
1011                 case 'H':       /* that's 'hh' in format */
1012                         if (is_sign) {
1013                                 signed char *s = (signed char *) va_arg(args,signed char *);
1014                                 *s = (signed char) simple_strtol(str,&next,base);
1015                         } else {
1016                                 unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
1017                                 *s = (unsigned char) simple_strtoul(str, &next, base);
1018                         }
1019                         break;
1020                 case 'h':
1021                         if (is_sign) {
1022                                 short *s = (short *) va_arg(args,short *);
1023                                 *s = (short) simple_strtol(str,&next,base);
1024                         } else {
1025                                 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
1026                                 *s = (unsigned short) simple_strtoul(str, &next, base);
1027                         }
1028                         break;
1029                 case 'l':
1030                         if (is_sign) {
1031                                 long *l = (long *) va_arg(args,long *);
1032                                 *l = simple_strtol(str,&next,base);
1033                         } else {
1034                                 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
1035                                 *l = simple_strtoul(str,&next,base);
1036                         }
1037                         break;
1038                 case 'L':
1039                         if (is_sign) {
1040                                 long long *l = (long long*) va_arg(args,long long *);
1041                                 *l = simple_strtoll(str,&next,base);
1042                         } else {
1043                                 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
1044                                 *l = simple_strtoull(str,&next,base);
1045                         }
1046                         break;
1047                 case 'Z':
1048                 case 'z':
1049                 {
1050                         size_t *s = (size_t*) va_arg(args,size_t*);
1051                         *s = (size_t) simple_strtoul(str,&next,base);
1052                 }
1053                 break;
1054                 default:
1055                         if (is_sign) {
1056                                 int *i = (int *) va_arg(args, int*);
1057                                 *i = (int) simple_strtol(str,&next,base);
1058                         } else {
1059                                 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
1060                                 *i = (unsigned int) simple_strtoul(str,&next,base);
1061                         }
1062                         break;
1063                 }
1064                 num++;
1065
1066                 if (!next)
1067                         break;
1068                 str = next;
1069         }
1070
1071         /*
1072          * Now we've come all the way through so either the input string or the
1073          * format ended. In the former case, there can be a %n at the current
1074          * position in the format that needs to be filled.
1075          */
1076         if (*fmt == '%' && *(fmt + 1) == 'n') {
1077                 int *p = (int *)va_arg(args, int *);
1078                 *p = str - buf;
1079         }
1080
1081         return num;
1082 }
1083
1084 EXPORT_SYMBOL(vsscanf);
1085
1086 /**
1087  * sscanf - Unformat a buffer into a list of arguments
1088  * @buf:        input buffer
1089  * @fmt:        formatting of buffer
1090  * @...:        resulting arguments
1091  */
1092 int sscanf(const char * buf, const char * fmt, ...)
1093 {
1094         va_list args;
1095         int i;
1096
1097         va_start(args,fmt);
1098         i = vsscanf(buf,fmt,args);
1099         va_end(args);
1100         return i;
1101 }
1102
1103 EXPORT_SYMBOL(sscanf);