Linux 2.6.22-rc3
[linux-2.6/next.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/page.h> /* for PAGE_SIZE */
27 #include <asm/div64.h>
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
35 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
37 unsigned long result = 0,value;
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;
49 } else if (base == 16) {
50 if (cp[0] == '0' && toupper(cp[1]) == 'X')
51 cp += 2;
53 while (isxdigit(*cp) &&
54 (value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) {
55 result = result*base + value;
56 cp++;
58 if (endp)
59 *endp = (char *)cp;
60 return result;
63 EXPORT_SYMBOL(simple_strtoul);
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
71 long simple_strtol(const char *cp,char **endp,unsigned int base)
73 if(*cp=='-')
74 return -simple_strtoul(cp+1,endp,base);
75 return simple_strtoul(cp,endp,base);
78 EXPORT_SYMBOL(simple_strtol);
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
86 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
88 unsigned long long result = 0,value;
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;
100 } else if (base == 16) {
101 if (cp[0] == '0' && toupper(cp[1]) == 'X')
102 cp += 2;
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++;
109 if (endp)
110 *endp = (char *)cp;
111 return result;
114 EXPORT_SYMBOL(simple_strtoull);
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
122 long long simple_strtoll(const char *cp,char **endp,unsigned int base)
124 if(*cp=='-')
125 return -simple_strtoull(cp+1,endp,base);
126 return simple_strtoull(cp,endp,base);
129 static int skip_atoi(const char **s)
131 int i=0;
133 while (isdigit(**s))
134 i = i*10 + *((*s)++) - '0';
135 return i;
138 #define ZEROPAD 1 /* pad with zero */
139 #define SIGN 2 /* unsigned/signed long */
140 #define PLUS 4 /* show plus */
141 #define SPACE 8 /* space if plus */
142 #define LEFT 16 /* left justified */
143 #define SPECIAL 32 /* 0x */
144 #define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */
146 static char * number(char * buf, char * end, unsigned long long num, int base, int size, int precision, int type)
148 char c,sign,tmp[66];
149 const char *digits;
150 static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
151 static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
152 int i;
154 digits = (type & LARGE) ? large_digits : small_digits;
155 if (type & LEFT)
156 type &= ~ZEROPAD;
157 if (base < 2 || base > 36)
158 return NULL;
159 c = (type & ZEROPAD) ? '0' : ' ';
160 sign = 0;
161 if (type & SIGN) {
162 if ((signed long long) num < 0) {
163 sign = '-';
164 num = - (signed long long) num;
165 size--;
166 } else if (type & PLUS) {
167 sign = '+';
168 size--;
169 } else if (type & SPACE) {
170 sign = ' ';
171 size--;
174 if (type & SPECIAL) {
175 if (base == 16)
176 size -= 2;
177 else if (base == 8)
178 size--;
180 i = 0;
181 if (num == 0)
182 tmp[i++]='0';
183 else while (num != 0)
184 tmp[i++] = digits[do_div(num,base)];
185 if (i > precision)
186 precision = i;
187 size -= precision;
188 if (!(type&(ZEROPAD+LEFT))) {
189 while(size-->0) {
190 if (buf < end)
191 *buf = ' ';
192 ++buf;
195 if (sign) {
196 if (buf < end)
197 *buf = sign;
198 ++buf;
200 if (type & SPECIAL) {
201 if (base==8) {
202 if (buf < end)
203 *buf = '0';
204 ++buf;
205 } else if (base==16) {
206 if (buf < end)
207 *buf = '0';
208 ++buf;
209 if (buf < end)
210 *buf = digits[33];
211 ++buf;
214 if (!(type & LEFT)) {
215 while (size-- > 0) {
216 if (buf < end)
217 *buf = c;
218 ++buf;
221 while (i < precision--) {
222 if (buf < end)
223 *buf = '0';
224 ++buf;
226 while (i-- > 0) {
227 if (buf < end)
228 *buf = tmp[i];
229 ++buf;
231 while (size-- > 0) {
232 if (buf < end)
233 *buf = ' ';
234 ++buf;
236 return buf;
240 * vsnprintf - Format a string and place it in a buffer
241 * @buf: The buffer to place the result into
242 * @size: The size of the buffer, including the trailing null space
243 * @fmt: The format string to use
244 * @args: Arguments for the format string
246 * The return value is the number of characters which would
247 * be generated for the given input, excluding the trailing
248 * '\0', as per ISO C99. If you want to have the exact
249 * number of characters written into @buf as return value
250 * (not including the trailing '\0'), use vscnprintf(). If the
251 * return is greater than or equal to @size, the resulting
252 * string is truncated.
254 * Call this function if you are already dealing with a va_list.
255 * You probably want snprintf() instead.
257 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
259 int len;
260 unsigned long long num;
261 int i, base;
262 char *str, *end, c;
263 const char *s;
265 int flags; /* flags to number() */
267 int field_width; /* width of output field */
268 int precision; /* min. # of digits for integers; max
269 number of chars for from string */
270 int qualifier; /* 'h', 'l', or 'L' for integer fields */
271 /* 'z' support added 23/7/1999 S.H. */
272 /* 'z' changed to 'Z' --davidm 1/25/99 */
273 /* 't' added for ptrdiff_t */
275 /* Reject out-of-range values early. Large positive sizes are
276 used for unknown buffer sizes. */
277 if (unlikely((int) size < 0)) {
278 /* There can be only one.. */
279 static int warn = 1;
280 WARN_ON(warn);
281 warn = 0;
282 return 0;
285 str = buf;
286 end = buf + size;
288 /* Make sure end is always >= buf */
289 if (end < buf) {
290 end = ((void *)-1);
291 size = end - buf;
294 for (; *fmt ; ++fmt) {
295 if (*fmt != '%') {
296 if (str < end)
297 *str = *fmt;
298 ++str;
299 continue;
302 /* process flags */
303 flags = 0;
304 repeat:
305 ++fmt; /* this also skips first '%' */
306 switch (*fmt) {
307 case '-': flags |= LEFT; goto repeat;
308 case '+': flags |= PLUS; goto repeat;
309 case ' ': flags |= SPACE; goto repeat;
310 case '#': flags |= SPECIAL; goto repeat;
311 case '0': flags |= ZEROPAD; goto repeat;
314 /* get field width */
315 field_width = -1;
316 if (isdigit(*fmt))
317 field_width = skip_atoi(&fmt);
318 else if (*fmt == '*') {
319 ++fmt;
320 /* it's the next argument */
321 field_width = va_arg(args, int);
322 if (field_width < 0) {
323 field_width = -field_width;
324 flags |= LEFT;
328 /* get the precision */
329 precision = -1;
330 if (*fmt == '.') {
331 ++fmt;
332 if (isdigit(*fmt))
333 precision = skip_atoi(&fmt);
334 else if (*fmt == '*') {
335 ++fmt;
336 /* it's the next argument */
337 precision = va_arg(args, int);
339 if (precision < 0)
340 precision = 0;
343 /* get the conversion qualifier */
344 qualifier = -1;
345 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
346 *fmt =='Z' || *fmt == 'z' || *fmt == 't') {
347 qualifier = *fmt;
348 ++fmt;
349 if (qualifier == 'l' && *fmt == 'l') {
350 qualifier = 'L';
351 ++fmt;
355 /* default base */
356 base = 10;
358 switch (*fmt) {
359 case 'c':
360 if (!(flags & LEFT)) {
361 while (--field_width > 0) {
362 if (str < end)
363 *str = ' ';
364 ++str;
367 c = (unsigned char) va_arg(args, int);
368 if (str < end)
369 *str = c;
370 ++str;
371 while (--field_width > 0) {
372 if (str < end)
373 *str = ' ';
374 ++str;
376 continue;
378 case 's':
379 s = va_arg(args, char *);
380 if ((unsigned long)s < PAGE_SIZE)
381 s = "<NULL>";
383 len = strnlen(s, precision);
385 if (!(flags & LEFT)) {
386 while (len < field_width--) {
387 if (str < end)
388 *str = ' ';
389 ++str;
392 for (i = 0; i < len; ++i) {
393 if (str < end)
394 *str = *s;
395 ++str; ++s;
397 while (len < field_width--) {
398 if (str < end)
399 *str = ' ';
400 ++str;
402 continue;
404 case 'p':
405 if (field_width == -1) {
406 field_width = 2*sizeof(void *);
407 flags |= ZEROPAD;
409 str = number(str, end,
410 (unsigned long) va_arg(args, void *),
411 16, field_width, precision, flags);
412 continue;
415 case 'n':
416 /* FIXME:
417 * What does C99 say about the overflow case here? */
418 if (qualifier == 'l') {
419 long * ip = va_arg(args, long *);
420 *ip = (str - buf);
421 } else if (qualifier == 'Z' || qualifier == 'z') {
422 size_t * ip = va_arg(args, size_t *);
423 *ip = (str - buf);
424 } else {
425 int * ip = va_arg(args, int *);
426 *ip = (str - buf);
428 continue;
430 case '%':
431 if (str < end)
432 *str = '%';
433 ++str;
434 continue;
436 /* integer number formats - set up the flags and "break" */
437 case 'o':
438 base = 8;
439 break;
441 case 'X':
442 flags |= LARGE;
443 case 'x':
444 base = 16;
445 break;
447 case 'd':
448 case 'i':
449 flags |= SIGN;
450 case 'u':
451 break;
453 default:
454 if (str < end)
455 *str = '%';
456 ++str;
457 if (*fmt) {
458 if (str < end)
459 *str = *fmt;
460 ++str;
461 } else {
462 --fmt;
464 continue;
466 if (qualifier == 'L')
467 num = va_arg(args, long long);
468 else if (qualifier == 'l') {
469 num = va_arg(args, unsigned long);
470 if (flags & SIGN)
471 num = (signed long) num;
472 } else if (qualifier == 'Z' || qualifier == 'z') {
473 num = va_arg(args, size_t);
474 } else if (qualifier == 't') {
475 num = va_arg(args, ptrdiff_t);
476 } else if (qualifier == 'h') {
477 num = (unsigned short) va_arg(args, int);
478 if (flags & SIGN)
479 num = (signed short) num;
480 } else {
481 num = va_arg(args, unsigned int);
482 if (flags & SIGN)
483 num = (signed int) num;
485 str = number(str, end, num, base,
486 field_width, precision, flags);
488 if (size > 0) {
489 if (str < end)
490 *str = '\0';
491 else
492 end[-1] = '\0';
494 /* the trailing null byte doesn't count towards the total */
495 return str-buf;
498 EXPORT_SYMBOL(vsnprintf);
501 * vscnprintf - Format a string and place it in a buffer
502 * @buf: The buffer to place the result into
503 * @size: The size of the buffer, including the trailing null space
504 * @fmt: The format string to use
505 * @args: Arguments for the format string
507 * The return value is the number of characters which have been written into
508 * the @buf not including the trailing '\0'. If @size is <= 0 the function
509 * returns 0.
511 * Call this function if you are already dealing with a va_list.
512 * You probably want scnprintf() instead.
514 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
516 int i;
518 i=vsnprintf(buf,size,fmt,args);
519 return (i >= size) ? (size - 1) : i;
522 EXPORT_SYMBOL(vscnprintf);
525 * snprintf - Format a string and place it in a buffer
526 * @buf: The buffer to place the result into
527 * @size: The size of the buffer, including the trailing null space
528 * @fmt: The format string to use
529 * @...: Arguments for the format string
531 * The return value is the number of characters which would be
532 * generated for the given input, excluding the trailing null,
533 * as per ISO C99. If the return is greater than or equal to
534 * @size, the resulting string is truncated.
536 int snprintf(char * buf, size_t size, const char *fmt, ...)
538 va_list args;
539 int i;
541 va_start(args, fmt);
542 i=vsnprintf(buf,size,fmt,args);
543 va_end(args);
544 return i;
547 EXPORT_SYMBOL(snprintf);
550 * scnprintf - Format a string and place it in a buffer
551 * @buf: The buffer to place the result into
552 * @size: The size of the buffer, including the trailing null space
553 * @fmt: The format string to use
554 * @...: Arguments for the format string
556 * The return value is the number of characters written into @buf not including
557 * the trailing '\0'. If @size is <= 0 the function returns 0.
560 int scnprintf(char * buf, size_t size, const char *fmt, ...)
562 va_list args;
563 int i;
565 va_start(args, fmt);
566 i = vsnprintf(buf, size, fmt, args);
567 va_end(args);
568 return (i >= size) ? (size - 1) : i;
570 EXPORT_SYMBOL(scnprintf);
573 * vsprintf - Format a string and place it in a buffer
574 * @buf: The buffer to place the result into
575 * @fmt: The format string to use
576 * @args: Arguments for the format string
578 * The function returns the number of characters written
579 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
580 * buffer overflows.
582 * Call this function if you are already dealing with a va_list.
583 * You probably want sprintf() instead.
585 int vsprintf(char *buf, const char *fmt, va_list args)
587 return vsnprintf(buf, INT_MAX, fmt, args);
590 EXPORT_SYMBOL(vsprintf);
593 * sprintf - Format a string and place it in a buffer
594 * @buf: The buffer to place the result into
595 * @fmt: The format string to use
596 * @...: Arguments for the format string
598 * The function returns the number of characters written
599 * into @buf. Use snprintf() or scnprintf() in order to avoid
600 * buffer overflows.
602 int sprintf(char * buf, const char *fmt, ...)
604 va_list args;
605 int i;
607 va_start(args, fmt);
608 i=vsnprintf(buf, INT_MAX, fmt, args);
609 va_end(args);
610 return i;
613 EXPORT_SYMBOL(sprintf);
616 * vsscanf - Unformat a buffer into a list of arguments
617 * @buf: input buffer
618 * @fmt: format of buffer
619 * @args: arguments
621 int vsscanf(const char * buf, const char * fmt, va_list args)
623 const char *str = buf;
624 char *next;
625 char digit;
626 int num = 0;
627 int qualifier;
628 int base;
629 int field_width;
630 int is_sign = 0;
632 while(*fmt && *str) {
633 /* skip any white space in format */
634 /* white space in format matchs any amount of
635 * white space, including none, in the input.
637 if (isspace(*fmt)) {
638 while (isspace(*fmt))
639 ++fmt;
640 while (isspace(*str))
641 ++str;
644 /* anything that is not a conversion must match exactly */
645 if (*fmt != '%' && *fmt) {
646 if (*fmt++ != *str++)
647 break;
648 continue;
651 if (!*fmt)
652 break;
653 ++fmt;
655 /* skip this conversion.
656 * advance both strings to next white space
658 if (*fmt == '*') {
659 while (!isspace(*fmt) && *fmt)
660 fmt++;
661 while (!isspace(*str) && *str)
662 str++;
663 continue;
666 /* get field width */
667 field_width = -1;
668 if (isdigit(*fmt))
669 field_width = skip_atoi(&fmt);
671 /* get conversion qualifier */
672 qualifier = -1;
673 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
674 *fmt == 'Z' || *fmt == 'z') {
675 qualifier = *fmt++;
676 if (unlikely(qualifier == *fmt)) {
677 if (qualifier == 'h') {
678 qualifier = 'H';
679 fmt++;
680 } else if (qualifier == 'l') {
681 qualifier = 'L';
682 fmt++;
686 base = 10;
687 is_sign = 0;
689 if (!*fmt || !*str)
690 break;
692 switch(*fmt++) {
693 case 'c':
695 char *s = (char *) va_arg(args,char*);
696 if (field_width == -1)
697 field_width = 1;
698 do {
699 *s++ = *str++;
700 } while (--field_width > 0 && *str);
701 num++;
703 continue;
704 case 's':
706 char *s = (char *) va_arg(args, char *);
707 if(field_width == -1)
708 field_width = INT_MAX;
709 /* first, skip leading white space in buffer */
710 while (isspace(*str))
711 str++;
713 /* now copy until next white space */
714 while (*str && !isspace(*str) && field_width--) {
715 *s++ = *str++;
717 *s = '\0';
718 num++;
720 continue;
721 case 'n':
722 /* return number of characters read so far */
724 int *i = (int *)va_arg(args,int*);
725 *i = str - buf;
727 continue;
728 case 'o':
729 base = 8;
730 break;
731 case 'x':
732 case 'X':
733 base = 16;
734 break;
735 case 'i':
736 base = 0;
737 case 'd':
738 is_sign = 1;
739 case 'u':
740 break;
741 case '%':
742 /* looking for '%' in str */
743 if (*str++ != '%')
744 return num;
745 continue;
746 default:
747 /* invalid format; stop here */
748 return num;
751 /* have some sort of integer conversion.
752 * first, skip white space in buffer.
754 while (isspace(*str))
755 str++;
757 digit = *str;
758 if (is_sign && digit == '-')
759 digit = *(str + 1);
761 if (!digit
762 || (base == 16 && !isxdigit(digit))
763 || (base == 10 && !isdigit(digit))
764 || (base == 8 && (!isdigit(digit) || digit > '7'))
765 || (base == 0 && !isdigit(digit)))
766 break;
768 switch(qualifier) {
769 case 'H': /* that's 'hh' in format */
770 if (is_sign) {
771 signed char *s = (signed char *) va_arg(args,signed char *);
772 *s = (signed char) simple_strtol(str,&next,base);
773 } else {
774 unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
775 *s = (unsigned char) simple_strtoul(str, &next, base);
777 break;
778 case 'h':
779 if (is_sign) {
780 short *s = (short *) va_arg(args,short *);
781 *s = (short) simple_strtol(str,&next,base);
782 } else {
783 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
784 *s = (unsigned short) simple_strtoul(str, &next, base);
786 break;
787 case 'l':
788 if (is_sign) {
789 long *l = (long *) va_arg(args,long *);
790 *l = simple_strtol(str,&next,base);
791 } else {
792 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
793 *l = simple_strtoul(str,&next,base);
795 break;
796 case 'L':
797 if (is_sign) {
798 long long *l = (long long*) va_arg(args,long long *);
799 *l = simple_strtoll(str,&next,base);
800 } else {
801 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
802 *l = simple_strtoull(str,&next,base);
804 break;
805 case 'Z':
806 case 'z':
808 size_t *s = (size_t*) va_arg(args,size_t*);
809 *s = (size_t) simple_strtoul(str,&next,base);
811 break;
812 default:
813 if (is_sign) {
814 int *i = (int *) va_arg(args, int*);
815 *i = (int) simple_strtol(str,&next,base);
816 } else {
817 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
818 *i = (unsigned int) simple_strtoul(str,&next,base);
820 break;
822 num++;
824 if (!next)
825 break;
826 str = next;
830 * Now we've come all the way through so either the input string or the
831 * format ended. In the former case, there can be a %n at the current
832 * position in the format that needs to be filled.
834 if (*fmt == '%' && *(fmt + 1) == 'n') {
835 int *p = (int *)va_arg(args, int *);
836 *p = str - buf;
839 return num;
842 EXPORT_SYMBOL(vsscanf);
845 * sscanf - Unformat a buffer into a list of arguments
846 * @buf: input buffer
847 * @fmt: formatting of buffer
848 * @...: resulting arguments
850 int sscanf(const char * buf, const char * fmt, ...)
852 va_list args;
853 int i;
855 va_start(args,fmt);
856 i = vsscanf(buf,fmt,args);
857 va_end(args);
858 return i;
861 EXPORT_SYMBOL(sscanf);
864 /* Simplified asprintf. */
865 char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
867 unsigned int len;
868 char *p;
869 va_list aq;
871 va_copy(aq, ap);
872 len = vsnprintf(NULL, 0, fmt, aq);
873 va_end(aq);
875 p = kmalloc(len+1, gfp);
876 if (!p)
877 return NULL;
879 vsnprintf(p, len+1, fmt, ap);
881 return p;
883 EXPORT_SYMBOL(kvasprintf);
885 char *kasprintf(gfp_t gfp, const char *fmt, ...)
887 va_list ap;
888 char *p;
890 va_start(ap, fmt);
891 p = kvasprintf(gfp, fmt, ap);
892 va_end(ap);
894 return p;
896 EXPORT_SYMBOL(kasprintf);