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 /* Works only for digits and letters, but small and fast */
  30 #define TOLOWER(x) ((x) | 0x20)
  31
  32 /**
  33  * simple_strtoul - convert a string to an unsigned long
  34  * @cp: The start of the string
  35  * @endp: A pointer to the end of the parsed string will be placed here
  36  * @base: The number base to use
  37  */
  38 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  39 {
  40         unsigned long result = 0,value;
  41
  42         if (!base) {
  43                 base = 10;
  44                 if (*cp == '0') {
  45                         base = 8;
  46                         cp++;
  47                         if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
  48                                 cp++;
  49                                 base = 16;
  50                         }
  51                 }
  52         } else if (base == 16) {
  53                 if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  54                         cp += 2;
  55         }
  56         while (isxdigit(*cp) &&
  57                (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
  58                 result = result*base + value;
  59                 cp++;
  60         }
  61         if (endp)
  62                 *endp = (char *)cp;
  63         return result;
  64 }
  65
  66 EXPORT_SYMBOL(simple_strtoul);
  67
  68 /**
  69  * simple_strtol - convert a string to a signed long
  70  * @cp: The start of the string
  71  * @endp: A pointer to the end of the parsed string will be placed here
  72  * @base: The number base to use
  73  */
  74 long simple_strtol(const char *cp,char **endp,unsigned int base)
  75 {
  76         if(*cp=='-')
  77                 return -simple_strtoul(cp+1,endp,base);
  78         return simple_strtoul(cp,endp,base);
  79 }
  80
  81 EXPORT_SYMBOL(simple_strtol);
  82
  83 /**
  84  * simple_strtoull - convert a string to an unsigned long long
  85  * @cp: The start of the string
  86  * @endp: A pointer to the end of the parsed string will be placed here
  87  * @base: The number base to use
  88  */
  89 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
  90 {
  91         unsigned long long result = 0,value;
  92
  93         if (!base) {
  94                 base = 10;
  95                 if (*cp == '0') {
  96                         base = 8;
  97                         cp++;
  98                         if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
  99                                 cp++;
 100                                 base = 16;
 101                         }
 102                 }
 103         } else if (base == 16) {
 104                 if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
 105                         cp += 2;
 106         }
 107         while (isxdigit(*cp)
 108          && (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
 109                 result = result*base + value;
 110                 cp++;
 111         }
 112         if (endp)
 113                 *endp = (char *)cp;
 114         return result;
 115 }
 116
 117 EXPORT_SYMBOL(simple_strtoull);
 118
 119 /**
 120  * simple_strtoll - convert a string to a signed long long
 121  * @cp: The start of the string
 122  * @endp: A pointer to the end of the parsed string will be placed here
 123  * @base: The number base to use
 124  */
 125 long long simple_strtoll(const char *cp,char **endp,unsigned int base)
 126 {
 127         if(*cp=='-')
 128                 return -simple_strtoull(cp+1,endp,base);
 129         return simple_strtoull(cp,endp,base);
 130 }
 131
 132
 133 /**
 134  * strict_strtoul - convert a string to an unsigned long strictly
 135  * @cp: The string to be converted
 136  * @base: The number base to use
 137  * @res: The converted result value
 138  *
 139  * strict_strtoul converts a string to an unsigned long only if the
 140  * string is really an unsigned long string, any string containing
 141  * any invalid char at the tail will be rejected and -EINVAL is returned,
 142  * only a newline char at the tail is acceptible because people generally
 143  * change a module parameter in the following way:
 144  *
 145  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 146  *
 147  * echo will append a newline to the tail.
 148  *
 149  * It returns 0 if conversion is successful and *res is set to the converted
 150  * value, otherwise it returns -EINVAL and *res is set to 0.
 151  *
 152  * simple_strtoul just ignores the successive invalid characters and
 153  * return the converted value of prefix part of the string.
 154  */
 155 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
 156
 157 /**
 158  * strict_strtol - convert a string to a long strictly
 159  * @cp: The string to be converted
 160  * @base: The number base to use
 161  * @res: The converted result value
 162  *
 163  * strict_strtol is similiar to strict_strtoul, but it allows the first
 164  * character of a string is '-'.
 165  *
 166  * It returns 0 if conversion is successful and *res is set to the converted
 167  * value, otherwise it returns -EINVAL and *res is set to 0.
 168  */
 169 int strict_strtol(const char *cp, unsigned int base, long *res);
 170
 171 /**
 172  * strict_strtoull - convert a string to an unsigned long long strictly
 173  * @cp: The string to be converted
 174  * @base: The number base to use
 175  * @res: The converted result value
 176  *
 177  * strict_strtoull converts a string to an unsigned long long only if the
 178  * string is really an unsigned long long string, any string containing
 179  * any invalid char at the tail will be rejected and -EINVAL is returned,
 180  * only a newline char at the tail is acceptible because people generally
 181  * change a module parameter in the following way:
 182  *
 183  *      echo 1024 > /sys/module/e1000/parameters/copybreak
 184  *
 185  * echo will append a newline to the tail of the string.
 186  *
 187  * It returns 0 if conversion is successful and *res is set to the converted
 188  * value, otherwise it returns -EINVAL and *res is set to 0.
 189  *
 190  * simple_strtoull just ignores the successive invalid characters and
 191  * return the converted value of prefix part of the string.
 192  */
 193 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);
 194
 195 /**
 196  * strict_strtoll - convert a string to a long long strictly
 197  * @cp: The string to be converted
 198  * @base: The number base to use
 199  * @res: The converted result value
 200  *
 201  * strict_strtoll is similiar to strict_strtoull, but it allows the first
 202  * character of a string is '-'.
 203  *
 204  * It returns 0 if conversion is successful and *res is set to the converted
 205  * value, otherwise it returns -EINVAL and *res is set to 0.
 206  */
 207 int strict_strtoll(const char *cp, unsigned int base, long long *res);
 208
 209 #define define_strict_strtoux(type, valtype)                            \
 210 int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\
 211 {                                                                       \
 212         char *tail;                                                     \
 213         valtype val;                                                    \
 214         size_t len;                                                     \
 215                                                                         \
 216         *res = 0;                                                       \
 217         len = strlen(cp);                                               \
 218         if (len == 0)                                                   \
 219                 return -EINVAL;                                         \
 220                                                                         \
 221         val = simple_strtoul(cp, &tail, base);                          \
 222         if ((*tail == '\0') ||                                          \
 223                 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {\
 224                 *res = val;                                             \
 225                 return 0;                                               \
 226         }                                                               \
 227                                                                         \
 228         return -EINVAL;                                                 \
 229 }                                                                       \
 230
 231 #define define_strict_strtox(type, valtype)                             \
 232 int strict_strto##type(const char *cp, unsigned int base, valtype *res) \
 233 {                                                                       \
 234         int ret;                                                        \
 235         if (*cp == '-') {                                               \
 236                 ret = strict_strtou##type(cp+1, base, res);             \
 237 <<<<<<< HEAD:lib/vsprintf.c
 238                 if (ret != 0)                                           \
 239 =======
 240                 if (!ret)                                               \
 241 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:lib/vsprintf.c
 242                         *res = -(*res);                                 \
 243         } else                                                          \
 244                 ret = strict_strtou##type(cp, base, res);               \
 245                                                                         \
 246         return ret;                                                     \
 247 }                                                                       \
 248
 249 define_strict_strtoux(l, unsigned long)
 250 define_strict_strtox(l, long)
 251 define_strict_strtoux(ll, unsigned long long)
 252 define_strict_strtox(ll, long long)
 253
 254 EXPORT_SYMBOL(strict_strtoul);
 255 EXPORT_SYMBOL(strict_strtol);
 256 EXPORT_SYMBOL(strict_strtoll);
 257 EXPORT_SYMBOL(strict_strtoull);
 258
 259 static int skip_atoi(const char **s)
 260 {
 261         int i=0;
 262
 263         while (isdigit(**s))
 264                 i = i*10 + *((*s)++) - '0';
 265         return i;
 266 }
 267
 268 /* Decimal conversion is by far the most typical, and is used
 269  * for /proc and /sys data. This directly impacts e.g. top performance
 270  * with many processes running. We optimize it for speed
 271  * using code from
 272  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
 273  * (with permission from the author, Douglas W. Jones). */
 274
 275 /* Formats correctly any integer in [0,99999].
 276  * Outputs from one to five digits depending on input.
 277  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
 278 static char* put_dec_trunc(char *buf, unsigned q)
 279 {
 280         unsigned d3, d2, d1, d0;
 281         d1 = (q>>4) & 0xf;
 282         d2 = (q>>8) & 0xf;
 283         d3 = (q>>12);
 284
 285         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 286         q = (d0 * 0xcd) >> 11;
 287         d0 = d0 - 10*q;
 288         *buf++ = d0 + '0'; /* least significant digit */
 289         d1 = q + 9*d3 + 5*d2 + d1;
 290         if (d1 != 0) {
 291                 q = (d1 * 0xcd) >> 11;
 292                 d1 = d1 - 10*q;
 293                 *buf++ = d1 + '0'; /* next digit */
 294
 295                 d2 = q + 2*d2;
 296                 if ((d2 != 0) || (d3 != 0)) {
 297                         q = (d2 * 0xd) >> 7;
 298                         d2 = d2 - 10*q;
 299                         *buf++ = d2 + '0'; /* next digit */
 300
 301                         d3 = q + 4*d3;
 302                         if (d3 != 0) {
 303                                 q = (d3 * 0xcd) >> 11;
 304                                 d3 = d3 - 10*q;
 305                                 *buf++ = d3 + '0';  /* next digit */
 306                                 if (q != 0)
 307                                         *buf++ = q + '0';  /* most sign. digit */
 308                         }
 309                 }
 310         }
 311         return buf;
 312 }
 313 /* Same with if's removed. Always emits five digits */
 314 static char* put_dec_full(char *buf, unsigned q)
 315 {
 316         /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
 317         /* but anyway, gcc produces better code with full-sized ints */
 318         unsigned d3, d2, d1, d0;
 319         d1 = (q>>4) & 0xf;
 320         d2 = (q>>8) & 0xf;
 321         d3 = (q>>12);
 322
 323         /* Possible ways to approx. divide by 10 */
 324         /* gcc -O2 replaces multiply with shifts and adds */
 325         // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
 326         // (x * 0x67) >> 10:  1100111
 327         // (x * 0x34) >> 9:    110100 - same
 328         // (x * 0x1a) >> 8:     11010 - same
 329         // (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
 330
 331         d0 = 6*(d3 + d2 + d1) + (q & 0xf);
 332         q = (d0 * 0xcd) >> 11;
 333         d0 = d0 - 10*q;
 334         *buf++ = d0 + '0';
 335         d1 = q + 9*d3 + 5*d2 + d1;
 336                 q = (d1 * 0xcd) >> 11;
 337                 d1 = d1 - 10*q;
 338                 *buf++ = d1 + '0';
 339
 340                 d2 = q + 2*d2;
 341                         q = (d2 * 0xd) >> 7;
 342                         d2 = d2 - 10*q;
 343                         *buf++ = d2 + '0';
 344
 345                         d3 = q + 4*d3;
 346                                 q = (d3 * 0xcd) >> 11; /* - shorter code */
 347                                 /* q = (d3 * 0x67) >> 10; - would also work */
 348                                 d3 = d3 - 10*q;
 349                                 *buf++ = d3 + '0';
 350                                         *buf++ = q + '0';
 351         return buf;
 352 }
 353 /* No inlining helps gcc to use registers better */
 354 static noinline char* put_dec(char *buf, unsigned long long num)
 355 {
 356         while (1) {
 357                 unsigned rem;
 358                 if (num < 100000)
 359                         return put_dec_trunc(buf, num);
 360                 rem = do_div(num, 100000);
 361                 buf = put_dec_full(buf, rem);
 362         }
 363 }
 364
 365 #define ZEROPAD 1               /* pad with zero */
 366 #define SIGN    2               /* unsigned/signed long */
 367 #define PLUS    4               /* show plus */
 368 #define SPACE   8               /* space if plus */
 369 #define LEFT    16              /* left justified */
 370 #define SMALL   32              /* Must be 32 == 0x20 */
 371 #define SPECIAL 64              /* 0x */
 372
 373 static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
 374 {
 375         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 376         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 377
 378         char tmp[66];
 379         char sign;
 380         char locase;
 381         int need_pfx = ((type & SPECIAL) && base != 10);
 382         int i;
 383
 384         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
 385          * produces same digits or (maybe lowercased) letters */
 386         locase = (type & SMALL);
 387         if (type & LEFT)
 388                 type &= ~ZEROPAD;
 389         sign = 0;
 390         if (type & SIGN) {
 391                 if ((signed long long) num < 0) {
 392                         sign = '-';
 393                         num = - (signed long long) num;
 394                         size--;
 395                 } else if (type & PLUS) {
 396                         sign = '+';
 397                         size--;
 398                 } else if (type & SPACE) {
 399                         sign = ' ';
 400                         size--;
 401                 }
 402         }
 403         if (need_pfx) {
 404                 size--;
 405                 if (base == 16)
 406                         size--;
 407         }
 408
 409         /* generate full string in tmp[], in reverse order */
 410         i = 0;
 411         if (num == 0)
 412                 tmp[i++] = '0';
 413         /* Generic code, for any base:
 414         else do {
 415                 tmp[i++] = (digits[do_div(num,base)] | locase);
 416         } while (num != 0);
 417         */
 418         else if (base != 10) { /* 8 or 16 */
 419                 int mask = base - 1;
 420                 int shift = 3;
 421                 if (base == 16) shift = 4;
 422                 do {
 423                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
 424                         num >>= shift;
 425                 } while (num);
 426         } else { /* base 10 */
 427                 i = put_dec(tmp, num) - tmp;
 428         }
 429
 430         /* printing 100 using %2d gives "100", not "00" */
 431         if (i > precision)
 432                 precision = i;
 433         /* leading space padding */
 434         size -= precision;
 435         if (!(type & (ZEROPAD+LEFT))) {
 436                 while(--size >= 0) {
 437                         if (buf < end)
 438                                 *buf = ' ';
 439                         ++buf;
 440                 }
 441         }
 442         /* sign */
 443         if (sign) {
 444                 if (buf < end)
 445                         *buf = sign;
 446                 ++buf;
 447         }
 448         /* "0x" / "0" prefix */
 449         if (need_pfx) {
 450                 if (buf < end)
 451                         *buf = '0';
 452                 ++buf;
 453                 if (base == 16) {
 454                         if (buf < end)
 455                                 *buf = ('X' | locase);
 456                         ++buf;
 457                 }
 458         }
 459         /* zero or space padding */
 460         if (!(type & LEFT)) {
 461                 char c = (type & ZEROPAD) ? '0' : ' ';
 462                 while (--size >= 0) {
 463                         if (buf < end)
 464                                 *buf = c;
 465                         ++buf;
 466                 }
 467         }
 468         /* hmm even more zero padding? */
 469         while (i <= --precision) {
 470                 if (buf < end)
 471                         *buf = '0';
 472                 ++buf;
 473         }
 474         /* actual digits of result */
 475         while (--i >= 0) {
 476                 if (buf < end)
 477                         *buf = tmp[i];
 478                 ++buf;
 479         }
 480         /* trailing space padding */
 481         while (--size >= 0) {
 482                 if (buf < end)
 483                         *buf = ' ';
 484                 ++buf;
 485         }
 486         return buf;
 487 }
 488
 489 /**
 490  * vsnprintf - Format a string and place it in a buffer
 491  * @buf: The buffer to place the result into
 492  * @size: The size of the buffer, including the trailing null space
 493  * @fmt: The format string to use
 494  * @args: Arguments for the format string
 495  *
 496  * The return value is the number of characters which would
 497  * be generated for the given input, excluding the trailing
 498  * '\0', as per ISO C99. If you want to have the exact
 499  * number of characters written into @buf as return value
 500  * (not including the trailing '\0'), use vscnprintf(). If the
 501  * return is greater than or equal to @size, the resulting
 502  * string is truncated.
 503  *
 504  * Call this function if you are already dealing with a va_list.
 505  * You probably want snprintf() instead.
 506  */
 507 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 508 {
 509         int len;
 510         unsigned long long num;
 511         int i, base;
 512         char *str, *end, c;
 513         const char *s;
 514
 515         int flags;              /* flags to number() */
 516
 517         int field_width;        /* width of output field */
 518         int precision;          /* min. # of digits for integers; max
 519                                    number of chars for from string */
 520         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 521                                 /* 'z' support added 23/7/1999 S.H.    */
 522                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 523                                 /* 't' added for ptrdiff_t */
 524
 525         /* Reject out-of-range values early.  Large positive sizes are
 526            used for unknown buffer sizes. */
 527         if (unlikely((int) size < 0)) {
 528                 /* There can be only one.. */
 529                 static char warn = 1;
 530                 WARN_ON(warn);
 531                 warn = 0;
 532                 return 0;
 533         }
 534
 535         str = buf;
 536         end = buf + size;
 537
 538         /* Make sure end is always >= buf */
 539         if (end < buf) {
 540                 end = ((void *)-1);
 541                 size = end - buf;
 542         }
 543
 544         for (; *fmt ; ++fmt) {
 545                 if (*fmt != '%') {
 546                         if (str < end)
 547                                 *str = *fmt;
 548                         ++str;
 549                         continue;
 550                 }
 551
 552                 /* process flags */
 553                 flags = 0;
 554                 repeat:
 555                         ++fmt;          /* this also skips first '%' */
 556                         switch (*fmt) {
 557                                 case '-': flags |= LEFT; goto repeat;
 558                                 case '+': flags |= PLUS; goto repeat;
 559                                 case ' ': flags |= SPACE; goto repeat;
 560                                 case '#': flags |= SPECIAL; goto repeat;
 561                                 case '0': flags |= ZEROPAD; goto repeat;
 562                         }
 563
 564                 /* get field width */
 565                 field_width = -1;
 566                 if (isdigit(*fmt))
 567                         field_width = skip_atoi(&fmt);
 568                 else if (*fmt == '*') {
 569                         ++fmt;
 570                         /* it's the next argument */
 571                         field_width = va_arg(args, int);
 572                         if (field_width < 0) {
 573                                 field_width = -field_width;
 574                                 flags |= LEFT;
 575                         }
 576                 }
 577
 578                 /* get the precision */
 579                 precision = -1;
 580                 if (*fmt == '.') {
 581                         ++fmt;
 582                         if (isdigit(*fmt))
 583                                 precision = skip_atoi(&fmt);
 584                         else if (*fmt == '*') {
 585                                 ++fmt;
 586                                 /* it's the next argument */
 587                                 precision = va_arg(args, int);
 588                         }
 589                         if (precision < 0)
 590                                 precision = 0;
 591                 }
 592
 593                 /* get the conversion qualifier */
 594                 qualifier = -1;
 595                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 596                     *fmt =='Z' || *fmt == 'z' || *fmt == 't') {
 597                         qualifier = *fmt;
 598                         ++fmt;
 599                         if (qualifier == 'l' && *fmt == 'l') {
 600                                 qualifier = 'L';
 601                                 ++fmt;
 602                         }
 603                 }
 604
 605                 /* default base */
 606                 base = 10;
 607
 608                 switch (*fmt) {
 609                         case 'c':
 610                                 if (!(flags & LEFT)) {
 611                                         while (--field_width > 0) {
 612                                                 if (str < end)
 613                                                         *str = ' ';
 614                                                 ++str;
 615                                         }
 616                                 }
 617                                 c = (unsigned char) va_arg(args, int);
 618                                 if (str < end)
 619                                         *str = c;
 620                                 ++str;
 621                                 while (--field_width > 0) {
 622                                         if (str < end)
 623                                                 *str = ' ';
 624                                         ++str;
 625                                 }
 626                                 continue;
 627
 628                         case 's':
 629                                 s = va_arg(args, char *);
 630                                 if ((unsigned long)s < PAGE_SIZE)
 631                                         s = "<NULL>";
 632
 633                                 len = strnlen(s, precision);
 634
 635                                 if (!(flags & LEFT)) {
 636                                         while (len < field_width--) {
 637                                                 if (str < end)
 638                                                         *str = ' ';
 639                                                 ++str;
 640                                         }
 641                                 }
 642                                 for (i = 0; i < len; ++i) {
 643                                         if (str < end)
 644                                                 *str = *s;
 645                                         ++str; ++s;
 646                                 }
 647                                 while (len < field_width--) {
 648                                         if (str < end)
 649                                                 *str = ' ';
 650                                         ++str;
 651                                 }
 652                                 continue;
 653
 654                         case 'p':
 655                                 flags |= SMALL;
 656                                 if (field_width == -1) {
 657                                         field_width = 2*sizeof(void *);
 658                                         flags |= ZEROPAD;
 659                                 }
 660                                 str = number(str, end,
 661                                                 (unsigned long) va_arg(args, void *),
 662                                                 16, field_width, precision, flags);
 663                                 continue;
 664
 665
 666                         case 'n':
 667                                 /* FIXME:
 668                                 * What does C99 say about the overflow case here? */
 669                                 if (qualifier == 'l') {
 670                                         long * ip = va_arg(args, long *);
 671                                         *ip = (str - buf);
 672                                 } else if (qualifier == 'Z' || qualifier == 'z') {
 673                                         size_t * ip = va_arg(args, size_t *);
 674                                         *ip = (str - buf);
 675                                 } else {
 676                                         int * ip = va_arg(args, int *);
 677                                         *ip = (str - buf);
 678                                 }
 679                                 continue;
 680
 681                         case '%':
 682                                 if (str < end)
 683                                         *str = '%';
 684                                 ++str;
 685                                 continue;
 686
 687                                 /* integer number formats - set up the flags and "break" */
 688                         case 'o':
 689                                 base = 8;
 690                                 break;
 691
 692                         case 'x':
 693                                 flags |= SMALL;
 694                         case 'X':
 695                                 base = 16;
 696                                 break;
 697
 698                         case 'd':
 699                         case 'i':
 700                                 flags |= SIGN;
 701                         case 'u':
 702                                 break;
 703
 704                         default:
 705                                 if (str < end)
 706                                         *str = '%';
 707                                 ++str;
 708                                 if (*fmt) {
 709                                         if (str < end)
 710                                                 *str = *fmt;
 711                                         ++str;
 712                                 } else {
 713                                         --fmt;
 714                                 }
 715                                 continue;
 716                 }
 717                 if (qualifier == 'L')
 718                         num = va_arg(args, long long);
 719                 else if (qualifier == 'l') {
 720                         num = va_arg(args, unsigned long);
 721                         if (flags & SIGN)
 722                                 num = (signed long) num;
 723                 } else if (qualifier == 'Z' || qualifier == 'z') {
 724                         num = va_arg(args, size_t);
 725                 } else if (qualifier == 't') {
 726                         num = va_arg(args, ptrdiff_t);
 727                 } else if (qualifier == 'h') {
 728                         num = (unsigned short) va_arg(args, int);
 729                         if (flags & SIGN)
 730                                 num = (signed short) num;
 731                 } else {
 732                         num = va_arg(args, unsigned int);
 733                         if (flags & SIGN)
 734                                 num = (signed int) num;
 735                 }
 736                 str = number(str, end, num, base,
 737                                 field_width, precision, flags);
 738         }
 739         if (size > 0) {
 740                 if (str < end)
 741                         *str = '\0';
 742                 else
 743                         end[-1] = '\0';
 744         }
 745         /* the trailing null byte doesn't count towards the total */
 746         return str-buf;
 747 }
 748
 749 EXPORT_SYMBOL(vsnprintf);
 750
 751 /**
 752  * vscnprintf - Format a string and place it in a buffer
 753  * @buf: The buffer to place the result into
 754  * @size: The size of the buffer, including the trailing null space
 755  * @fmt: The format string to use
 756  * @args: Arguments for the format string
 757  *
 758  * The return value is the number of characters which have been written into
 759  * the @buf not including the trailing '\0'. If @size is <= 0 the function
 760  * returns 0.
 761  *
 762  * Call this function if you are already dealing with a va_list.
 763  * You probably want scnprintf() instead.
 764  */
 765 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 766 {
 767         int i;
 768
 769         i=vsnprintf(buf,size,fmt,args);
 770         return (i >= size) ? (size - 1) : i;
 771 }
 772
 773 EXPORT_SYMBOL(vscnprintf);
 774
 775 /**
 776  * snprintf - Format a string and place it in a buffer
 777  * @buf: The buffer to place the result into
 778  * @size: The size of the buffer, including the trailing null space
 779  * @fmt: The format string to use
 780  * @...: Arguments for the format string
 781  *
 782  * The return value is the number of characters which would be
 783  * generated for the given input, excluding the trailing null,
 784  * as per ISO C99.  If the return is greater than or equal to
 785  * @size, the resulting string is truncated.
 786  */
 787 int snprintf(char * buf, size_t size, const char *fmt, ...)
 788 {
 789         va_list args;
 790         int i;
 791
 792         va_start(args, fmt);
 793         i=vsnprintf(buf,size,fmt,args);
 794         va_end(args);
 795         return i;
 796 }
 797
 798 EXPORT_SYMBOL(snprintf);
 799
 800 /**
 801  * scnprintf - Format a string and place it in a buffer
 802  * @buf: The buffer to place the result into
 803  * @size: The size of the buffer, including the trailing null space
 804  * @fmt: The format string to use
 805  * @...: Arguments for the format string
 806  *
 807  * The return value is the number of characters written into @buf not including
 808  * the trailing '\0'. If @size is <= 0 the function returns 0.
 809  */
 810
 811 int scnprintf(char * buf, size_t size, const char *fmt, ...)
 812 {
 813         va_list args;
 814         int i;
 815
 816         va_start(args, fmt);
 817         i = vsnprintf(buf, size, fmt, args);
 818         va_end(args);
 819         return (i >= size) ? (size - 1) : i;
 820 }
 821 EXPORT_SYMBOL(scnprintf);
 822
 823 /**
 824  * vsprintf - Format a string and place it in a buffer
 825  * @buf: The buffer to place the result into
 826  * @fmt: The format string to use
 827  * @args: Arguments for the format string
 828  *
 829  * The function returns the number of characters written
 830  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
 831  * buffer overflows.
 832  *
 833  * Call this function if you are already dealing with a va_list.
 834  * You probably want sprintf() instead.
 835  */
 836 int vsprintf(char *buf, const char *fmt, va_list args)
 837 {
 838         return vsnprintf(buf, INT_MAX, fmt, args);
 839 }
 840
 841 EXPORT_SYMBOL(vsprintf);
 842
 843 /**
 844  * sprintf - Format a string and place it in a buffer
 845  * @buf: The buffer to place the result into
 846  * @fmt: The format string to use
 847  * @...: Arguments for the format string
 848  *
 849  * The function returns the number of characters written
 850  * into @buf. Use snprintf() or scnprintf() in order to avoid
 851  * buffer overflows.
 852  */
 853 int sprintf(char * buf, const char *fmt, ...)
 854 {
 855         va_list args;
 856         int i;
 857
 858         va_start(args, fmt);
 859         i=vsnprintf(buf, INT_MAX, fmt, args);
 860         va_end(args);
 861         return i;
 862 }
 863
 864 EXPORT_SYMBOL(sprintf);
 865
 866 /**
 867  * vsscanf - Unformat a buffer into a list of arguments
 868  * @buf:        input buffer
 869  * @fmt:        format of buffer
 870  * @args:       arguments
 871  */
 872 int vsscanf(const char * buf, const char * fmt, va_list args)
 873 {
 874         const char *str = buf;
 875         char *next;
 876         char digit;
 877         int num = 0;
 878         int qualifier;
 879         int base;
 880         int field_width;
 881         int is_sign = 0;
 882
 883         while(*fmt && *str) {
 884                 /* skip any white space in format */
 885                 /* white space in format matchs any amount of
 886                  * white space, including none, in the input.
 887                  */
 888                 if (isspace(*fmt)) {
 889                         while (isspace(*fmt))
 890                                 ++fmt;
 891                         while (isspace(*str))
 892                                 ++str;
 893                 }
 894
 895                 /* anything that is not a conversion must match exactly */
 896                 if (*fmt != '%' && *fmt) {
 897                         if (*fmt++ != *str++)
 898                                 break;
 899                         continue;
 900                 }
 901
 902                 if (!*fmt)
 903                         break;
 904                 ++fmt;
 905
 906                 /* skip this conversion.
 907                  * advance both strings to next white space
 908                  */
 909                 if (*fmt == '*') {
 910                         while (!isspace(*fmt) && *fmt)
 911                                 fmt++;
 912                         while (!isspace(*str) && *str)
 913                                 str++;
 914                         continue;
 915                 }
 916
 917                 /* get field width */
 918                 field_width = -1;
 919                 if (isdigit(*fmt))
 920                         field_width = skip_atoi(&fmt);
 921
 922                 /* get conversion qualifier */
 923                 qualifier = -1;
 924                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 925                     *fmt == 'Z' || *fmt == 'z') {
 926                         qualifier = *fmt++;
 927                         if (unlikely(qualifier == *fmt)) {
 928                                 if (qualifier == 'h') {
 929                                         qualifier = 'H';
 930                                         fmt++;
 931                                 } else if (qualifier == 'l') {
 932                                         qualifier = 'L';
 933                                         fmt++;
 934                                 }
 935                         }
 936                 }
 937                 base = 10;
 938                 is_sign = 0;
 939
 940                 if (!*fmt || !*str)
 941                         break;
 942
 943                 switch(*fmt++) {
 944                 case 'c':
 945                 {
 946                         char *s = (char *) va_arg(args,char*);
 947                         if (field_width == -1)
 948                                 field_width = 1;
 949                         do {
 950                                 *s++ = *str++;
 951                         } while (--field_width > 0 && *str);
 952                         num++;
 953                 }
 954                 continue;
 955                 case 's':
 956                 {
 957                         char *s = (char *) va_arg(args, char *);
 958                         if(field_width == -1)
 959                                 field_width = INT_MAX;
 960                         /* first, skip leading white space in buffer */
 961                         while (isspace(*str))
 962                                 str++;
 963
 964                         /* now copy until next white space */
 965                         while (*str && !isspace(*str) && field_width--) {
 966                                 *s++ = *str++;
 967                         }
 968                         *s = '\0';
 969                         num++;
 970                 }
 971                 continue;
 972                 case 'n':
 973                         /* return number of characters read so far */
 974                 {
 975                         int *i = (int *)va_arg(args,int*);
 976                         *i = str - buf;
 977                 }
 978                 continue;
 979                 case 'o':
 980                         base = 8;
 981                         break;
 982                 case 'x':
 983                 case 'X':
 984                         base = 16;
 985                         break;
 986                 case 'i':
 987                         base = 0;
 988                 case 'd':
 989                         is_sign = 1;
 990                 case 'u':
 991                         break;
 992                 case '%':
 993                         /* looking for '%' in str */
 994                         if (*str++ != '%')
 995                                 return num;
 996                         continue;
 997                 default:
 998                         /* invalid format; stop here */
 999                         return num;
1000                 }
1001
1002                 /* have some sort of integer conversion.
1003                  * first, skip white space in buffer.
1004                  */
1005                 while (isspace(*str))
1006                         str++;
1007
1008                 digit = *str;
1009                 if (is_sign && digit == '-')
1010                         digit = *(str + 1);
1011
1012                 if (!digit
1013                     || (base == 16 && !isxdigit(digit))
1014                     || (base == 10 && !isdigit(digit))
1015                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1016                     || (base == 0 && !isdigit(digit)))
1017                                 break;
1018
1019                 switch(qualifier) {
1020                 case 'H':       /* that's 'hh' in format */
1021                         if (is_sign) {
1022                                 signed char *s = (signed char *) va_arg(args,signed char *);
1023                                 *s = (signed char) simple_strtol(str,&next,base);
1024                         } else {
1025                                 unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
1026                                 *s = (unsigned char) simple_strtoul(str, &next, base);
1027                         }
1028                         break;
1029                 case 'h':
1030                         if (is_sign) {
1031                                 short *s = (short *) va_arg(args,short *);
1032                                 *s = (short) simple_strtol(str,&next,base);
1033                         } else {
1034                                 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
1035                                 *s = (unsigned short) simple_strtoul(str, &next, base);
1036                         }
1037                         break;
1038                 case 'l':
1039                         if (is_sign) {
1040                                 long *l = (long *) va_arg(args,long *);
1041                                 *l = simple_strtol(str,&next,base);
1042                         } else {
1043                                 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
1044                                 *l = simple_strtoul(str,&next,base);
1045                         }
1046                         break;
1047                 case 'L':
1048                         if (is_sign) {
1049                                 long long *l = (long long*) va_arg(args,long long *);
1050                                 *l = simple_strtoll(str,&next,base);
1051                         } else {
1052                                 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
1053                                 *l = simple_strtoull(str,&next,base);
1054                         }
1055                         break;
1056                 case 'Z':
1057                 case 'z':
1058                 {
1059                         size_t *s = (size_t*) va_arg(args,size_t*);
1060                         *s = (size_t) simple_strtoul(str,&next,base);
1061                 }
1062                 break;
1063                 default:
1064                         if (is_sign) {
1065                                 int *i = (int *) va_arg(args, int*);
1066                                 *i = (int) simple_strtol(str,&next,base);
1067                         } else {
1068                                 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
1069                                 *i = (unsigned int) simple_strtoul(str,&next,base);
1070                         }
1071                         break;
1072                 }
1073                 num++;
1074
1075                 if (!next)
1076                         break;
1077                 str = next;
1078         }
1079
1080         /*
1081          * Now we've come all the way through so either the input string or the
1082          * format ended. In the former case, there can be a %n at the current
1083          * position in the format that needs to be filled.
1084          */
1085         if (*fmt == '%' && *(fmt + 1) == 'n') {
1086                 int *p = (int *)va_arg(args, int *);
1087                 *p = str - buf;
1088         }
1089
1090         return num;
1091 }
1092
1093 EXPORT_SYMBOL(vsscanf);
1094
1095 /**
1096  * sscanf - Unformat a buffer into a list of arguments
1097  * @buf:        input buffer
1098  * @fmt:        formatting of buffer
1099  * @...:        resulting arguments
1100  */
1101 int sscanf(const char * buf, const char * fmt, ...)
1102 {
1103         va_list args;
1104         int i;
1105
1106         va_start(args,fmt);
1107         i = vsscanf(buf,fmt,args);
1108         va_end(args);
1109         return i;
1110 }
1111
1112 EXPORT_SYMBOL(sscanf);