4 * Copyright (C) 1991, 1992 Linus Torvalds
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
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
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>
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;
44 if ((toupper(*cp) == 'X') && isxdigit(cp[1])) {
49 } else if (base == 16) {
50 if (cp[0] == '0' && toupper(cp[1]) == 'X')
53 while (isxdigit(*cp) &&
54 (value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) {
55 result = result*base + value;
63 EXPORT_SYMBOL(simple_strtoul);
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)
74 return -simple_strtoul(cp+1,endp,base);
75 return simple_strtoul(cp,endp,base);
78 EXPORT_SYMBOL(simple_strtol);
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;
95 if ((toupper(*cp) == 'X') && isxdigit(cp[1])) {
100 } else if (base == 16) {
101 if (cp[0] == '0' && toupper(cp[1]) == 'X')
104 while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
105 ? toupper(*cp) : *cp)-'A'+10) < base) {
106 result = result*base + value;
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)
125 return -simple_strtoull(cp+1,endp,base);
126 return simple_strtoull(cp,endp,base);
131 * strict_strtoul - convert a string to an unsigned long strictly
132 * @cp: The string to be converted
133 * @base: The number base to use
134 * @res: The converted result value
136 * strict_strtoul converts a string to an unsigned long only if the
137 * string is really an unsigned long string, any string containing
138 * any invalid char at the tail will be rejected and -EINVAL is returned,
139 * only a newline char at the tail is acceptible because people generally
140 * change a module parameter in the following way:
142 * echo 1024 > /sys/module/e1000/parameters/copybreak
144 * echo will append a newline to the tail.
146 * It returns 0 if conversion is successful and *res is set to the converted
147 * value, otherwise it returns -EINVAL and *res is set to 0.
149 * simple_strtoul just ignores the successive invalid characters and
150 * return the converted value of prefix part of the string.
152 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
155 * strict_strtol - convert a string to a long strictly
156 * @cp: The string to be converted
157 * @base: The number base to use
158 * @res: The converted result value
160 * strict_strtol is similiar to strict_strtoul, but it allows the first
161 * character of a string is '-'.
163 * It returns 0 if conversion is successful and *res is set to the converted
164 * value, otherwise it returns -EINVAL and *res is set to 0.
166 int strict_strtol(const char *cp, unsigned int base, long *res);
169 * strict_strtoull - convert a string to an unsigned long long strictly
170 * @cp: The string to be converted
171 * @base: The number base to use
172 * @res: The converted result value
174 * strict_strtoull converts a string to an unsigned long long only if the
175 * string is really an unsigned long long string, any string containing
176 * any invalid char at the tail will be rejected and -EINVAL is returned,
177 * only a newline char at the tail is acceptible because people generally
178 * change a module parameter in the following way:
180 * echo 1024 > /sys/module/e1000/parameters/copybreak
182 * echo will append a newline to the tail of the string.
184 * It returns 0 if conversion is successful and *res is set to the converted
185 * value, otherwise it returns -EINVAL and *res is set to 0.
187 * simple_strtoull just ignores the successive invalid characters and
188 * return the converted value of prefix part of the string.
190 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);
193 * strict_strtoll - convert a string to a long long strictly
194 * @cp: The string to be converted
195 * @base: The number base to use
196 * @res: The converted result value
198 * strict_strtoll is similiar to strict_strtoull, but it allows the first
199 * character of a string is '-'.
201 * It returns 0 if conversion is successful and *res is set to the converted
202 * value, otherwise it returns -EINVAL and *res is set to 0.
204 int strict_strtoll(const char *cp, unsigned int base, long long *res);
206 #define define_strict_strtoux(type, valtype) \
207 int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\
218 val = simple_strtoul(cp, &tail, base); \
219 if ((*tail == '\0') || \
220 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {\
228 #define define_strict_strtox(type, valtype) \
229 int strict_strto##type(const char *cp, unsigned int base, valtype *res) \
233 ret = strict_strtou##type(cp+1, base, res); \
237 ret = strict_strtou##type(cp, base, res); \
242 define_strict_strtoux(l, unsigned long)
243 define_strict_strtox(l, long)
244 define_strict_strtoux(ll, unsigned long long)
245 define_strict_strtox(ll, long long)
247 EXPORT_SYMBOL(strict_strtoul);
248 EXPORT_SYMBOL(strict_strtol);
249 EXPORT_SYMBOL(strict_strtoll);
250 EXPORT_SYMBOL(strict_strtoull);
252 static int skip_atoi(const char **s)
257 i = i*10 + *((*s)++) - '0';
261 /* Decimal conversion is by far the most typical, and is used
262 * for /proc and /sys data. This directly impacts e.g. top performance
263 * with many processes running. We optimize it for speed
265 * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
266 * (with permission from the author, Douglas W. Jones). */
268 /* Formats correctly any integer in [0,99999].
269 * Outputs from one to five digits depending on input.
270 * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
271 static char* put_dec_trunc(char *buf, unsigned q)
273 unsigned d3, d2, d1, d0;
278 d0 = 6*(d3 + d2 + d1) + (q & 0xf);
279 q = (d0 * 0xcd) >> 11;
281 *buf++ = d0 + '0'; /* least significant digit */
282 d1 = q + 9*d3 + 5*d2 + d1;
284 q = (d1 * 0xcd) >> 11;
286 *buf++ = d1 + '0'; /* next digit */
289 if ((d2 != 0) || (d3 != 0)) {
292 *buf++ = d2 + '0'; /* next digit */
296 q = (d3 * 0xcd) >> 11;
298 *buf++ = d3 + '0'; /* next digit */
300 *buf++ = q + '0'; /* most sign. digit */
306 /* Same with if's removed. Always emits five digits */
307 static char* put_dec_full(char *buf, unsigned q)
309 /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
310 /* but anyway, gcc produces better code with full-sized ints */
311 unsigned d3, d2, d1, d0;
316 /* Possible ways to approx. divide by 10 */
317 /* gcc -O2 replaces multiply with shifts and adds */
318 // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
319 // (x * 0x67) >> 10: 1100111
320 // (x * 0x34) >> 9: 110100 - same
321 // (x * 0x1a) >> 8: 11010 - same
322 // (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
324 d0 = 6*(d3 + d2 + d1) + (q & 0xf);
325 q = (d0 * 0xcd) >> 11;
328 d1 = q + 9*d3 + 5*d2 + d1;
329 q = (d1 * 0xcd) >> 11;
339 q = (d3 * 0xcd) >> 11; /* - shorter code */
340 /* q = (d3 * 0x67) >> 10; - would also work */
346 /* No inlining helps gcc to use registers better */
347 static noinline char* put_dec(char *buf, unsigned long long num)
352 return put_dec_trunc(buf, num);
353 rem = do_div(num, 100000);
354 buf = put_dec_full(buf, rem);
358 #define ZEROPAD 1 /* pad with zero */
359 #define SIGN 2 /* unsigned/signed long */
360 #define PLUS 4 /* show plus */
361 #define SPACE 8 /* space if plus */
362 #define LEFT 16 /* left justified */
363 #define SPECIAL 32 /* 0x */
364 #define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */
366 static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
370 /* we are called with base 8, 10 or 16, only, thus don't need "g..." */
371 static const char small_digits[] = "0123456789abcdefx"; /* "ghijklmnopqrstuvwxyz"; */
372 static const char large_digits[] = "0123456789ABCDEFX"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
373 int need_pfx = ((type & SPECIAL) && base != 10);
376 digits = (type & LARGE) ? large_digits : small_digits;
379 if (base < 2 || base > 36)
383 if ((signed long long) num < 0) {
385 num = - (signed long long) num;
387 } else if (type & PLUS) {
390 } else if (type & SPACE) {
401 /* generate full string in tmp[], in reverse order */
405 /* Generic code, for any base:
407 tmp[i++] = digits[do_div(num,base)];
410 else if (base != 10) { /* 8 or 16 */
413 if (base == 16) shift = 4;
415 tmp[i++] = digits[((unsigned char)num) & mask];
418 } else { /* base 10 */
419 i = put_dec(tmp, num) - tmp;
422 /* printing 100 using %2d gives "100", not "00" */
425 /* leading space padding */
427 if (!(type & (ZEROPAD+LEFT))) {
440 /* "0x" / "0" prefix */
447 *buf = digits[16]; /* for arbitrary base: digits[33]; */
451 /* zero or space padding */
452 if (!(type & LEFT)) {
453 char c = (type & ZEROPAD) ? '0' : ' ';
454 while (--size >= 0) {
460 /* hmm even more zero padding? */
461 while (i <= --precision) {
466 /* actual digits of result */
472 /* trailing space padding */
473 while (--size >= 0) {
482 * vsnprintf - Format a string and place it in a buffer
483 * @buf: The buffer to place the result into
484 * @size: The size of the buffer, including the trailing null space
485 * @fmt: The format string to use
486 * @args: Arguments for the format string
488 * The return value is the number of characters which would
489 * be generated for the given input, excluding the trailing
490 * '\0', as per ISO C99. If you want to have the exact
491 * number of characters written into @buf as return value
492 * (not including the trailing '\0'), use vscnprintf(). If the
493 * return is greater than or equal to @size, the resulting
494 * string is truncated.
496 * Call this function if you are already dealing with a va_list.
497 * You probably want snprintf() instead.
499 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
502 unsigned long long num;
507 int flags; /* flags to number() */
509 int field_width; /* width of output field */
510 int precision; /* min. # of digits for integers; max
511 number of chars for from string */
512 int qualifier; /* 'h', 'l', or 'L' for integer fields */
513 /* 'z' support added 23/7/1999 S.H. */
514 /* 'z' changed to 'Z' --davidm 1/25/99 */
515 /* 't' added for ptrdiff_t */
517 /* Reject out-of-range values early. Large positive sizes are
518 used for unknown buffer sizes. */
519 if (unlikely((int) size < 0)) {
520 /* There can be only one.. */
521 static char warn = 1;
530 /* Make sure end is always >= buf */
536 for (; *fmt ; ++fmt) {
547 ++fmt; /* this also skips first '%' */
549 case '-': flags |= LEFT; goto repeat;
550 case '+': flags |= PLUS; goto repeat;
551 case ' ': flags |= SPACE; goto repeat;
552 case '#': flags |= SPECIAL; goto repeat;
553 case '0': flags |= ZEROPAD; goto repeat;
556 /* get field width */
559 field_width = skip_atoi(&fmt);
560 else if (*fmt == '*') {
562 /* it's the next argument */
563 field_width = va_arg(args, int);
564 if (field_width < 0) {
565 field_width = -field_width;
570 /* get the precision */
575 precision = skip_atoi(&fmt);
576 else if (*fmt == '*') {
578 /* it's the next argument */
579 precision = va_arg(args, int);
585 /* get the conversion qualifier */
587 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
588 *fmt =='Z' || *fmt == 'z' || *fmt == 't') {
591 if (qualifier == 'l' && *fmt == 'l') {
602 if (!(flags & LEFT)) {
603 while (--field_width > 0) {
609 c = (unsigned char) va_arg(args, int);
613 while (--field_width > 0) {
621 s = va_arg(args, char *);
622 if ((unsigned long)s < PAGE_SIZE)
625 len = strnlen(s, precision);
627 if (!(flags & LEFT)) {
628 while (len < field_width--) {
634 for (i = 0; i < len; ++i) {
639 while (len < field_width--) {
647 if (field_width == -1) {
648 field_width = 2*sizeof(void *);
651 str = number(str, end,
652 (unsigned long) va_arg(args, void *),
653 16, field_width, precision, flags);
659 * What does C99 say about the overflow case here? */
660 if (qualifier == 'l') {
661 long * ip = va_arg(args, long *);
663 } else if (qualifier == 'Z' || qualifier == 'z') {
664 size_t * ip = va_arg(args, size_t *);
667 int * ip = va_arg(args, int *);
678 /* integer number formats - set up the flags and "break" */
708 if (qualifier == 'L')
709 num = va_arg(args, long long);
710 else if (qualifier == 'l') {
711 num = va_arg(args, unsigned long);
713 num = (signed long) num;
714 } else if (qualifier == 'Z' || qualifier == 'z') {
715 num = va_arg(args, size_t);
716 } else if (qualifier == 't') {
717 num = va_arg(args, ptrdiff_t);
718 } else if (qualifier == 'h') {
719 num = (unsigned short) va_arg(args, int);
721 num = (signed short) num;
723 num = va_arg(args, unsigned int);
725 num = (signed int) num;
727 str = number(str, end, num, base,
728 field_width, precision, flags);
736 /* the trailing null byte doesn't count towards the total */
740 EXPORT_SYMBOL(vsnprintf);
743 * vscnprintf - Format a string and place it in a buffer
744 * @buf: The buffer to place the result into
745 * @size: The size of the buffer, including the trailing null space
746 * @fmt: The format string to use
747 * @args: Arguments for the format string
749 * The return value is the number of characters which have been written into
750 * the @buf not including the trailing '\0'. If @size is <= 0 the function
753 * Call this function if you are already dealing with a va_list.
754 * You probably want scnprintf() instead.
756 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
760 i=vsnprintf(buf,size,fmt,args);
761 return (i >= size) ? (size - 1) : i;
764 EXPORT_SYMBOL(vscnprintf);
767 * snprintf - Format a string and place it in a buffer
768 * @buf: The buffer to place the result into
769 * @size: The size of the buffer, including the trailing null space
770 * @fmt: The format string to use
771 * @...: Arguments for the format string
773 * The return value is the number of characters which would be
774 * generated for the given input, excluding the trailing null,
775 * as per ISO C99. If the return is greater than or equal to
776 * @size, the resulting string is truncated.
778 int snprintf(char * buf, size_t size, const char *fmt, ...)
784 i=vsnprintf(buf,size,fmt,args);
789 EXPORT_SYMBOL(snprintf);
792 * scnprintf - Format a string and place it in a buffer
793 * @buf: The buffer to place the result into
794 * @size: The size of the buffer, including the trailing null space
795 * @fmt: The format string to use
796 * @...: Arguments for the format string
798 * The return value is the number of characters written into @buf not including
799 * the trailing '\0'. If @size is <= 0 the function returns 0.
802 int scnprintf(char * buf, size_t size, const char *fmt, ...)
808 i = vsnprintf(buf, size, fmt, args);
810 return (i >= size) ? (size - 1) : i;
812 EXPORT_SYMBOL(scnprintf);
815 * vsprintf - Format a string and place it in a buffer
816 * @buf: The buffer to place the result into
817 * @fmt: The format string to use
818 * @args: Arguments for the format string
820 * The function returns the number of characters written
821 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
824 * Call this function if you are already dealing with a va_list.
825 * You probably want sprintf() instead.
827 int vsprintf(char *buf, const char *fmt, va_list args)
829 return vsnprintf(buf, INT_MAX, fmt, args);
832 EXPORT_SYMBOL(vsprintf);
835 * sprintf - Format a string and place it in a buffer
836 * @buf: The buffer to place the result into
837 * @fmt: The format string to use
838 * @...: Arguments for the format string
840 * The function returns the number of characters written
841 * into @buf. Use snprintf() or scnprintf() in order to avoid
844 int sprintf(char * buf, const char *fmt, ...)
850 i=vsnprintf(buf, INT_MAX, fmt, args);
855 EXPORT_SYMBOL(sprintf);
858 * vsscanf - Unformat a buffer into a list of arguments
860 * @fmt: format of buffer
863 int vsscanf(const char * buf, const char * fmt, va_list args)
865 const char *str = buf;
874 while(*fmt && *str) {
875 /* skip any white space in format */
876 /* white space in format matchs any amount of
877 * white space, including none, in the input.
880 while (isspace(*fmt))
882 while (isspace(*str))
886 /* anything that is not a conversion must match exactly */
887 if (*fmt != '%' && *fmt) {
888 if (*fmt++ != *str++)
897 /* skip this conversion.
898 * advance both strings to next white space
901 while (!isspace(*fmt) && *fmt)
903 while (!isspace(*str) && *str)
908 /* get field width */
911 field_width = skip_atoi(&fmt);
913 /* get conversion qualifier */
915 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
916 *fmt == 'Z' || *fmt == 'z') {
918 if (unlikely(qualifier == *fmt)) {
919 if (qualifier == 'h') {
922 } else if (qualifier == 'l') {
937 char *s = (char *) va_arg(args,char*);
938 if (field_width == -1)
942 } while (--field_width > 0 && *str);
948 char *s = (char *) va_arg(args, char *);
949 if(field_width == -1)
950 field_width = INT_MAX;
951 /* first, skip leading white space in buffer */
952 while (isspace(*str))
955 /* now copy until next white space */
956 while (*str && !isspace(*str) && field_width--) {
964 /* return number of characters read so far */
966 int *i = (int *)va_arg(args,int*);
984 /* looking for '%' in str */
989 /* invalid format; stop here */
993 /* have some sort of integer conversion.
994 * first, skip white space in buffer.
996 while (isspace(*str))
1000 if (is_sign && digit == '-')
1004 || (base == 16 && !isxdigit(digit))
1005 || (base == 10 && !isdigit(digit))
1006 || (base == 8 && (!isdigit(digit) || digit > '7'))
1007 || (base == 0 && !isdigit(digit)))
1011 case 'H': /* that's 'hh' in format */
1013 signed char *s = (signed char *) va_arg(args,signed char *);
1014 *s = (signed char) simple_strtol(str,&next,base);
1016 unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
1017 *s = (unsigned char) simple_strtoul(str, &next, base);
1022 short *s = (short *) va_arg(args,short *);
1023 *s = (short) simple_strtol(str,&next,base);
1025 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
1026 *s = (unsigned short) simple_strtoul(str, &next, base);
1031 long *l = (long *) va_arg(args,long *);
1032 *l = simple_strtol(str,&next,base);
1034 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
1035 *l = simple_strtoul(str,&next,base);
1040 long long *l = (long long*) va_arg(args,long long *);
1041 *l = simple_strtoll(str,&next,base);
1043 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
1044 *l = simple_strtoull(str,&next,base);
1050 size_t *s = (size_t*) va_arg(args,size_t*);
1051 *s = (size_t) simple_strtoul(str,&next,base);
1056 int *i = (int *) va_arg(args, int*);
1057 *i = (int) simple_strtol(str,&next,base);
1059 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
1060 *i = (unsigned int) simple_strtoul(str,&next,base);
1072 * Now we've come all the way through so either the input string or the
1073 * format ended. In the former case, there can be a %n at the current
1074 * position in the format that needs to be filled.
1076 if (*fmt == '%' && *(fmt + 1) == 'n') {
1077 int *p = (int *)va_arg(args, int *);
1084 EXPORT_SYMBOL(vsscanf);
1087 * sscanf - Unformat a buffer into a list of arguments
1088 * @buf: input buffer
1089 * @fmt: formatting of buffer
1090 * @...: resulting arguments
1092 int sscanf(const char * buf, const char * fmt, ...)
1098 i = vsscanf(buf,fmt,args);
1103 EXPORT_SYMBOL(sscanf);