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[linux-2.6/history.git] / lib / vsprintf.c
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1 /*
2 * linux/lib/vsprintf.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
8 /*
9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
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
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>
26 #include <asm/div64.h>
28 /**
29 * simple_strtoul - convert a string to an unsigned long
30 * @cp: The start of the string
31 * @endp: A pointer to the end of the parsed string will be placed here
32 * @base: The number base to use
34 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
36 unsigned long result = 0,value;
38 if (!base) {
39 base = 10;
40 if (*cp == '0') {
41 base = 8;
42 cp++;
43 if ((*cp == 'x') && isxdigit(cp[1])) {
44 cp++;
45 base = 16;
49 while (isxdigit(*cp) &&
50 (value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) {
51 result = result*base + value;
52 cp++;
54 if (endp)
55 *endp = (char *)cp;
56 return result;
59 EXPORT_SYMBOL(simple_strtoul);
61 /**
62 * simple_strtol - convert a string to a signed long
63 * @cp: The start of the string
64 * @endp: A pointer to the end of the parsed string will be placed here
65 * @base: The number base to use
67 long simple_strtol(const char *cp,char **endp,unsigned int base)
69 if(*cp=='-')
70 return -simple_strtoul(cp+1,endp,base);
71 return simple_strtoul(cp,endp,base);
74 EXPORT_SYMBOL(simple_strtol);
76 /**
77 * simple_strtoull - convert a string to an unsigned long long
78 * @cp: The start of the string
79 * @endp: A pointer to the end of the parsed string will be placed here
80 * @base: The number base to use
82 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
84 unsigned long long result = 0,value;
86 if (!base) {
87 base = 10;
88 if (*cp == '0') {
89 base = 8;
90 cp++;
91 if ((*cp == 'x') && isxdigit(cp[1])) {
92 cp++;
93 base = 16;
97 while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
98 ? toupper(*cp) : *cp)-'A'+10) < base) {
99 result = result*base + value;
100 cp++;
102 if (endp)
103 *endp = (char *)cp;
104 return result;
107 EXPORT_SYMBOL(simple_strtoull);
110 * simple_strtoll - convert a string to a signed long long
111 * @cp: The start of the string
112 * @endp: A pointer to the end of the parsed string will be placed here
113 * @base: The number base to use
115 long long simple_strtoll(const char *cp,char **endp,unsigned int base)
117 if(*cp=='-')
118 return -simple_strtoull(cp+1,endp,base);
119 return simple_strtoull(cp,endp,base);
122 static int skip_atoi(const char **s)
124 int i=0;
126 while (isdigit(**s))
127 i = i*10 + *((*s)++) - '0';
128 return i;
131 #define ZEROPAD 1 /* pad with zero */
132 #define SIGN 2 /* unsigned/signed long */
133 #define PLUS 4 /* show plus */
134 #define SPACE 8 /* space if plus */
135 #define LEFT 16 /* left justified */
136 #define SPECIAL 32 /* 0x */
137 #define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */
139 static char * number(char * buf, char * end, unsigned long long num, int base, int size, int precision, int type)
141 char c,sign,tmp[66];
142 const char *digits;
143 static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
144 static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
145 int i;
147 digits = (type & LARGE) ? large_digits : small_digits;
148 if (type & LEFT)
149 type &= ~ZEROPAD;
150 if (base < 2 || base > 36)
151 return 0;
152 c = (type & ZEROPAD) ? '0' : ' ';
153 sign = 0;
154 if (type & SIGN) {
155 if ((signed long long) num < 0) {
156 sign = '-';
157 num = - (signed long long) num;
158 size--;
159 } else if (type & PLUS) {
160 sign = '+';
161 size--;
162 } else if (type & SPACE) {
163 sign = ' ';
164 size--;
167 if (type & SPECIAL) {
168 if (base == 16)
169 size -= 2;
170 else if (base == 8)
171 size--;
173 i = 0;
174 if (num == 0)
175 tmp[i++]='0';
176 else while (num != 0)
177 tmp[i++] = digits[do_div(num,base)];
178 if (i > precision)
179 precision = i;
180 size -= precision;
181 if (!(type&(ZEROPAD+LEFT))) {
182 while(size-->0) {
183 if (buf <= end)
184 *buf = ' ';
185 ++buf;
188 if (sign) {
189 if (buf <= end)
190 *buf = sign;
191 ++buf;
193 if (type & SPECIAL) {
194 if (base==8) {
195 if (buf <= end)
196 *buf = '0';
197 ++buf;
198 } else if (base==16) {
199 if (buf <= end)
200 *buf = '0';
201 ++buf;
202 if (buf <= end)
203 *buf = digits[33];
204 ++buf;
207 if (!(type & LEFT)) {
208 while (size-- > 0) {
209 if (buf <= end)
210 *buf = c;
211 ++buf;
214 while (i < precision--) {
215 if (buf <= end)
216 *buf = '0';
217 ++buf;
219 while (i-- > 0) {
220 if (buf <= end)
221 *buf = tmp[i];
222 ++buf;
224 while (size-- > 0) {
225 if (buf <= end)
226 *buf = ' ';
227 ++buf;
229 return buf;
233 * vsnprintf - Format a string and place it in a buffer
234 * @buf: The buffer to place the result into
235 * @size: The size of the buffer, including the trailing null space
236 * @fmt: The format string to use
237 * @args: Arguments for the format string
239 * The return value is the number of characters which would
240 * be generated for the given input, excluding the trailing
241 * '\0', as per ISO C99. If you want to have the exact
242 * number of characters written into @buf as return value
243 * (not including the trailing '\0'), use vscnprintf. If the
244 * return is greater than or equal to @size, the resulting
245 * string is truncated.
247 * Call this function if you are already dealing with a va_list.
248 * You probably want snprintf instead.
250 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
252 int len;
253 unsigned long long num;
254 int i, base;
255 char *str, *end, c;
256 const char *s;
258 int flags; /* flags to number() */
260 int field_width; /* width of output field */
261 int precision; /* min. # of digits for integers; max
262 number of chars for from string */
263 int qualifier; /* 'h', 'l', or 'L' for integer fields */
264 /* 'z' support added 23/7/1999 S.H. */
265 /* 'z' changed to 'Z' --davidm 1/25/99 */
267 /* Reject out-of-range values early */
268 if (unlikely((int) size < 0)) {
269 /* There can be only one.. */
270 static int warn = 1;
271 WARN_ON(warn);
272 warn = 0;
273 return 0;
276 str = buf;
277 end = buf + size - 1;
279 if (end < buf - 1) {
280 end = ((void *) -1);
281 size = end - buf + 1;
284 for (; *fmt ; ++fmt) {
285 if (*fmt != '%') {
286 if (str <= end)
287 *str = *fmt;
288 ++str;
289 continue;
292 /* process flags */
293 flags = 0;
294 repeat:
295 ++fmt; /* this also skips first '%' */
296 switch (*fmt) {
297 case '-': flags |= LEFT; goto repeat;
298 case '+': flags |= PLUS; goto repeat;
299 case ' ': flags |= SPACE; goto repeat;
300 case '#': flags |= SPECIAL; goto repeat;
301 case '0': flags |= ZEROPAD; goto repeat;
304 /* get field width */
305 field_width = -1;
306 if (isdigit(*fmt))
307 field_width = skip_atoi(&fmt);
308 else if (*fmt == '*') {
309 ++fmt;
310 /* it's the next argument */
311 field_width = va_arg(args, int);
312 if (field_width < 0) {
313 field_width = -field_width;
314 flags |= LEFT;
318 /* get the precision */
319 precision = -1;
320 if (*fmt == '.') {
321 ++fmt;
322 if (isdigit(*fmt))
323 precision = skip_atoi(&fmt);
324 else if (*fmt == '*') {
325 ++fmt;
326 /* it's the next argument */
327 precision = va_arg(args, int);
329 if (precision < 0)
330 precision = 0;
333 /* get the conversion qualifier */
334 qualifier = -1;
335 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
336 *fmt =='Z' || *fmt == 'z') {
337 qualifier = *fmt;
338 ++fmt;
339 if (qualifier == 'l' && *fmt == 'l') {
340 qualifier = 'L';
341 ++fmt;
345 /* default base */
346 base = 10;
348 switch (*fmt) {
349 case 'c':
350 if (!(flags & LEFT)) {
351 while (--field_width > 0) {
352 if (str <= end)
353 *str = ' ';
354 ++str;
357 c = (unsigned char) va_arg(args, int);
358 if (str <= end)
359 *str = c;
360 ++str;
361 while (--field_width > 0) {
362 if (str <= end)
363 *str = ' ';
364 ++str;
366 continue;
368 case 's':
369 s = va_arg(args, char *);
370 if ((unsigned long)s < PAGE_SIZE)
371 s = "<NULL>";
373 len = strnlen(s, precision);
375 if (!(flags & LEFT)) {
376 while (len < field_width--) {
377 if (str <= end)
378 *str = ' ';
379 ++str;
382 for (i = 0; i < len; ++i) {
383 if (str <= end)
384 *str = *s;
385 ++str; ++s;
387 while (len < field_width--) {
388 if (str <= end)
389 *str = ' ';
390 ++str;
392 continue;
394 case 'p':
395 if (field_width == -1) {
396 field_width = 2*sizeof(void *);
397 flags |= ZEROPAD;
399 str = number(str, end,
400 (unsigned long) va_arg(args, void *),
401 16, field_width, precision, flags);
402 continue;
405 case 'n':
406 /* FIXME:
407 * What does C99 say about the overflow case here? */
408 if (qualifier == 'l') {
409 long * ip = va_arg(args, long *);
410 *ip = (str - buf);
411 } else if (qualifier == 'Z' || qualifier == 'z') {
412 size_t * ip = va_arg(args, size_t *);
413 *ip = (str - buf);
414 } else {
415 int * ip = va_arg(args, int *);
416 *ip = (str - buf);
418 continue;
420 case '%':
421 if (str <= end)
422 *str = '%';
423 ++str;
424 continue;
426 /* integer number formats - set up the flags and "break" */
427 case 'o':
428 base = 8;
429 break;
431 case 'X':
432 flags |= LARGE;
433 case 'x':
434 base = 16;
435 break;
437 case 'd':
438 case 'i':
439 flags |= SIGN;
440 case 'u':
441 break;
443 default:
444 if (str <= end)
445 *str = '%';
446 ++str;
447 if (*fmt) {
448 if (str <= end)
449 *str = *fmt;
450 ++str;
451 } else {
452 --fmt;
454 continue;
456 if (qualifier == 'L')
457 num = va_arg(args, long long);
458 else if (qualifier == 'l') {
459 num = va_arg(args, unsigned long);
460 if (flags & SIGN)
461 num = (signed long) num;
462 } else if (qualifier == 'Z' || qualifier == 'z') {
463 num = va_arg(args, size_t);
464 } else if (qualifier == 'h') {
465 num = (unsigned short) va_arg(args, int);
466 if (flags & SIGN)
467 num = (signed short) num;
468 } else {
469 num = va_arg(args, unsigned int);
470 if (flags & SIGN)
471 num = (signed int) num;
473 str = number(str, end, num, base,
474 field_width, precision, flags);
476 if (str <= end)
477 *str = '\0';
478 else if (size > 0)
479 /* don't write out a null byte if the buf size is zero */
480 *end = '\0';
481 /* the trailing null byte doesn't count towards the total
482 * ++str;
484 return str-buf;
487 EXPORT_SYMBOL(vsnprintf);
490 * vscnprintf - Format a string and place it in a buffer
491 * @buf: The buffer to place the result into
492 * @size: The size of the buffer, including the trailing null space
493 * @fmt: The format string to use
494 * @args: Arguments for the format string
496 * The return value is the number of characters which have been written into
497 * the @buf not including the trailing '\0'. If @size is <= 0 the function
498 * returns 0.
500 * Call this function if you are already dealing with a va_list.
501 * You probably want scnprintf instead.
503 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
505 int i;
507 i=vsnprintf(buf,size,fmt,args);
508 return (i >= size) ? (size - 1) : i;
511 EXPORT_SYMBOL(vscnprintf);
514 * snprintf - Format a string and place it in a buffer
515 * @buf: The buffer to place the result into
516 * @size: The size of the buffer, including the trailing null space
517 * @fmt: The format string to use
518 * @...: Arguments for the format string
520 * The return value is the number of characters which would be
521 * generated for the given input, excluding the trailing null,
522 * as per ISO C99. If the return is greater than or equal to
523 * @size, the resulting string is truncated.
525 int snprintf(char * buf, size_t size, const char *fmt, ...)
527 va_list args;
528 int i;
530 va_start(args, fmt);
531 i=vsnprintf(buf,size,fmt,args);
532 va_end(args);
533 return i;
536 EXPORT_SYMBOL(snprintf);
539 * scnprintf - Format a string and place it in a buffer
540 * @buf: The buffer to place the result into
541 * @size: The size of the buffer, including the trailing null space
542 * @fmt: The format string to use
543 * @...: Arguments for the format string
545 * The return value is the number of characters written into @buf not including
546 * the trailing '\0'. If @size is <= 0 the function returns 0. If the return is
547 * greater than or equal to @size, the resulting string is truncated.
550 int scnprintf(char * buf, size_t size, const char *fmt, ...)
552 va_list args;
553 int i;
555 va_start(args, fmt);
556 i = vsnprintf(buf, size, fmt, args);
557 va_end(args);
558 return (i >= size) ? (size - 1) : i;
560 EXPORT_SYMBOL(scnprintf);
563 * vsprintf - Format a string and place it in a buffer
564 * @buf: The buffer to place the result into
565 * @fmt: The format string to use
566 * @args: Arguments for the format string
568 * The function returns the number of characters written
569 * into @buf. Use vsnprintf or vscnprintf in order to avoid
570 * buffer overflows.
572 * Call this function if you are already dealing with a va_list.
573 * You probably want sprintf instead.
575 int vsprintf(char *buf, const char *fmt, va_list args)
577 return vsnprintf(buf, (~0U)>>1, fmt, args);
580 EXPORT_SYMBOL(vsprintf);
583 * sprintf - Format a string and place it in a buffer
584 * @buf: The buffer to place the result into
585 * @fmt: The format string to use
586 * @...: Arguments for the format string
588 * The function returns the number of characters written
589 * into @buf. Use snprintf or scnprintf in order to avoid
590 * buffer overflows.
592 int sprintf(char * buf, const char *fmt, ...)
594 va_list args;
595 int i;
597 va_start(args, fmt);
598 i=vsprintf(buf,fmt,args);
599 va_end(args);
600 return i;
603 EXPORT_SYMBOL(sprintf);
606 * vsscanf - Unformat a buffer into a list of arguments
607 * @buf: input buffer
608 * @fmt: format of buffer
609 * @args: arguments
611 int vsscanf(const char * buf, const char * fmt, va_list args)
613 const char *str = buf;
614 char *next;
615 char digit;
616 int num = 0;
617 int qualifier;
618 int base;
619 int field_width;
620 int is_sign = 0;
622 while(*fmt && *str) {
623 /* skip any white space in format */
624 /* white space in format matchs any amount of
625 * white space, including none, in the input.
627 if (isspace(*fmt)) {
628 while (isspace(*fmt))
629 ++fmt;
630 while (isspace(*str))
631 ++str;
634 /* anything that is not a conversion must match exactly */
635 if (*fmt != '%' && *fmt) {
636 if (*fmt++ != *str++)
637 break;
638 continue;
641 if (!*fmt)
642 break;
643 ++fmt;
645 /* skip this conversion.
646 * advance both strings to next white space
648 if (*fmt == '*') {
649 while (!isspace(*fmt) && *fmt)
650 fmt++;
651 while (!isspace(*str) && *str)
652 str++;
653 continue;
656 /* get field width */
657 field_width = -1;
658 if (isdigit(*fmt))
659 field_width = skip_atoi(&fmt);
661 /* get conversion qualifier */
662 qualifier = -1;
663 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
664 *fmt == 'Z' || *fmt == 'z') {
665 qualifier = *fmt;
666 fmt++;
668 base = 10;
669 is_sign = 0;
671 if (!*fmt || !*str)
672 break;
674 switch(*fmt++) {
675 case 'c':
677 char *s = (char *) va_arg(args,char*);
678 if (field_width == -1)
679 field_width = 1;
680 do {
681 *s++ = *str++;
682 } while (--field_width > 0 && *str);
683 num++;
685 continue;
686 case 's':
688 char *s = (char *) va_arg(args, char *);
689 if(field_width == -1)
690 field_width = INT_MAX;
691 /* first, skip leading white space in buffer */
692 while (isspace(*str))
693 str++;
695 /* now copy until next white space */
696 while (*str && !isspace(*str) && field_width--) {
697 *s++ = *str++;
699 *s = '\0';
700 num++;
702 continue;
703 case 'n':
704 /* return number of characters read so far */
706 int *i = (int *)va_arg(args,int*);
707 *i = str - buf;
709 continue;
710 case 'o':
711 base = 8;
712 break;
713 case 'x':
714 case 'X':
715 base = 16;
716 break;
717 case 'i':
718 base = 0;
719 case 'd':
720 is_sign = 1;
721 case 'u':
722 break;
723 case '%':
724 /* looking for '%' in str */
725 if (*str++ != '%')
726 return num;
727 continue;
728 default:
729 /* invalid format; stop here */
730 return num;
733 /* have some sort of integer conversion.
734 * first, skip white space in buffer.
736 while (isspace(*str))
737 str++;
739 digit = *str;
740 if (is_sign && digit == '-')
741 digit = *(str + 1);
743 if (!digit
744 || (base == 16 && !isxdigit(digit))
745 || (base == 10 && !isdigit(digit))
746 || (base == 8 && (!isdigit(digit) || digit > '7'))
747 || (base == 0 && !isdigit(digit)))
748 break;
750 switch(qualifier) {
751 case 'h':
752 if (is_sign) {
753 short *s = (short *) va_arg(args,short *);
754 *s = (short) simple_strtol(str,&next,base);
755 } else {
756 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
757 *s = (unsigned short) simple_strtoul(str, &next, base);
759 break;
760 case 'l':
761 if (is_sign) {
762 long *l = (long *) va_arg(args,long *);
763 *l = simple_strtol(str,&next,base);
764 } else {
765 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
766 *l = simple_strtoul(str,&next,base);
768 break;
769 case 'L':
770 if (is_sign) {
771 long long *l = (long long*) va_arg(args,long long *);
772 *l = simple_strtoll(str,&next,base);
773 } else {
774 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
775 *l = simple_strtoull(str,&next,base);
777 break;
778 case 'Z':
779 case 'z':
781 size_t *s = (size_t*) va_arg(args,size_t*);
782 *s = (size_t) simple_strtoul(str,&next,base);
784 break;
785 default:
786 if (is_sign) {
787 int *i = (int *) va_arg(args, int*);
788 *i = (int) simple_strtol(str,&next,base);
789 } else {
790 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
791 *i = (unsigned int) simple_strtoul(str,&next,base);
793 break;
795 num++;
797 if (!next)
798 break;
799 str = next;
801 return num;
804 EXPORT_SYMBOL(vsscanf);
807 * sscanf - Unformat a buffer into a list of arguments
808 * @buf: input buffer
809 * @fmt: formatting of buffer
810 * @...: resulting arguments
812 int sscanf(const char * buf, const char * fmt, ...)
814 va_list args;
815 int i;
817 va_start(args,fmt);
818 i = vsscanf(buf,fmt,args);
819 va_end(args);
820 return i;
823 EXPORT_SYMBOL(sscanf);