projects/linux·blob v2.6.24-rc3 · refs

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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 <[email protected]>
14 * - changed to provide snprintf and vsnprintf functions
15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <[email protected]>
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 */
35unsigned 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
63EXPORT_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 */
71long 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
78EXPORT_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 */
86unsigned 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
114EXPORT_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 */
122long 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
129static 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. */
148static 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 */
184static 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 */
224static 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
243static 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 */
376int 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
617EXPORT_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 */
633int 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
641EXPORT_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 */
655int 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
666EXPORT_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
679int 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}
689EXPORT_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 */
704int vsprintf(char *buf, const char *fmt, va_list args)
705{
706 return vsnprintf(buf, INT_MAX, fmt, args);
707}
708
709EXPORT_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 */
721int 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
732EXPORT_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 */
740int 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
961EXPORT_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 */
969int 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
980EXPORT_SYMBOL(sscanf);