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