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