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c3aac50f28
freebsd/sys/kern/subr_scanf.c
Peter Wemm c3aac50f28 $Id$ -> $FreeBSD$
1999-08-28 01:08:13 +00:00

794 lines
18 KiB
C
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/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
* From: Id: vfscanf.c,v 1.13 1998/09/25 12:20:27 obrien Exp
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <machine/limits.h>
/*
* Note that stdarg.h and the ANSI style va_start macro is used for both
* ANSI and traditional C compilers.
*/
#include <machine/stdarg.h>
#define BUF 32 /* Maximum length of numeric string. */
/*
* Flags used during conversion.
*/
#define LONG 0x01 /* l: long or double */
#define SHORT 0x04 /* h: short */
#define SUPPRESS 0x08 /* suppress assignment */
#define POINTER 0x10 /* weird %p pointer (`fake hex') */
#define NOSKIP 0x20 /* do not skip blanks */
#define QUAD 0x400
/*
* The following are used in numeric conversions only:
* SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
* SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
*/
#define SIGNOK 0x40 /* +/- is (still) legal */
#define NDIGITS 0x80 /* no digits detected */
#define DPTOK 0x100 /* (float) decimal point is still legal */
#define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */
#define PFXOK 0x100 /* 0x prefix is (still) legal */
#define NZDIGITS 0x200 /* no zero digits detected */
/*
* Conversion types.
*/
#define CT_CHAR 0 /* %c conversion */
#define CT_CCL 1 /* %[...] conversion */
#define CT_STRING 2 /* %s conversion */
#define CT_INT 3 /* integer, i.e., strtoq or strtouq */
typedef u_quad_t (*ccfntype)(const char *, const char **, int);
#define isspace(c) ((c) == ' ' || (c) == '\t' || \
(c) == '\r' || (c) == '\n')
#define isascii(c) (((c) & ~0x7f) == 0)
#define isupper(c) ((c) >= 'A' && (c) <= 'Z')
#define islower(c) ((c) >= 'a' && (c) <= 'z')
#define isalpha(c) (isupper(c) || (islower(c)))
#define isdigit(c) ((c) >= '0' && (c) <= '9')
static const u_char *__sccl(char *, const u_char *);
int
sscanf(const char *ibuf, const char *fmt, ...)
{
va_list ap;
int ret;
va_start(ap, fmt);
ret = vsscanf(ibuf, fmt, ap);
va_end(ap);
return(ret);
}
int
vsscanf(const char *inp, char const *fmt0, va_list ap)
{
int inr;
const u_char *fmt = (const u_char *)fmt0;
int c; /* character from format, or conversion */
size_t width; /* field width, or 0 */
char *p; /* points into all kinds of strings */
int n; /* handy integer */
int flags; /* flags as defined above */
char *p0; /* saves original value of p when necessary */
int nassigned; /* number of fields assigned */
int nconversions; /* number of conversions */
int nread; /* number of characters consumed from fp */
int base; /* base argument to strtoq/strtouq */
ccfntype ccfn; /* conversion function (strtoq/strtouq) */
char ccltab[256]; /* character class table for %[...] */
char buf[BUF]; /* buffer for numeric conversions */
/* `basefix' is used to avoid `if' tests in the integer scanner */
static short basefix[17] =
{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
inr = strlen(inp);
nassigned = 0;
nconversions = 0;
nread = 0;
base = 0; /* XXX just to keep gcc happy */
ccfn = NULL; /* XXX just to keep gcc happy */
for (;;) {
c = *fmt++;
if (c == 0)
return (nassigned);
if (isspace(c)) {
while (inr > 0 && isspace(*inp))
nread++, inr--, inp++;
continue;
}
if (c != '%')
goto literal;
width = 0;
flags = 0;
/*
* switch on the format. continue if done;
* break once format type is derived.
*/
again: c = *fmt++;
switch (c) {
case '%':
literal:
if (inr <= 0)
goto input_failure;
if (*inp != c)
goto match_failure;
inr--, inp++;
nread++;
continue;
case '*':
flags |= SUPPRESS;
goto again;
case 'l':
flags |= LONG;
goto again;
case 'q':
flags |= QUAD;
goto again;
case 'h':
flags |= SHORT;
goto again;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
width = width * 10 + c - '0';
goto again;
/*
* Conversions.
*
*/
case 'd':
c = CT_INT;
ccfn = (ccfntype)strtoq;
base = 10;
break;
case 'i':
c = CT_INT;
ccfn = (ccfntype)strtoq;
base = 0;
break;
case 'o':
c = CT_INT;
ccfn = strtouq;
base = 8;
break;
case 'u':
c = CT_INT;
ccfn = strtouq;
base = 10;
break;
case 'x':
flags |= PFXOK; /* enable 0x prefixing */
c = CT_INT;
ccfn = strtouq;
base = 16;
break;
case 's':
c = CT_STRING;
break;
case '[':
fmt = __sccl(ccltab, fmt);
flags |= NOSKIP;
c = CT_CCL;
break;
case 'c':
flags |= NOSKIP;
c = CT_CHAR;
break;
case 'p': /* pointer format is like hex */
flags |= POINTER | PFXOK;
c = CT_INT;
ccfn = strtouq;
base = 16;
break;
case 'n':
nconversions++;
if (flags & SUPPRESS) /* ??? */
continue;
if (flags & SHORT)
*va_arg(ap, short *) = nread;
else if (flags & LONG)
*va_arg(ap, long *) = nread;
else if (flags & QUAD)
*va_arg(ap, quad_t *) = nread;
else
*va_arg(ap, int *) = nread;
continue;
}
/*
* We have a conversion that requires input.
*/
if (inr <= 0)
goto input_failure;
/*
* Consume leading white space, except for formats
* that suppress this.
*/
if ((flags & NOSKIP) == 0) {
while (isspace(*inp)) {
nread++;
if (--inr > 0)
inp++;
else
goto input_failure;
}
/*
* Note that there is at least one character in
* the buffer, so conversions that do not set NOSKIP
* can no longer result in an input failure.
*/
}
/*
* Do the conversion.
*/
switch (c) {
case CT_CHAR:
/* scan arbitrary characters (sets NOSKIP) */
if (width == 0)
width = 1;
if (flags & SUPPRESS) {
size_t sum = 0;
for (;;) {
if ((n = inr) < width) {
sum += n;
width -= n;
inp += n;
if (sum == 0)
goto input_failure;
break;
} else {
sum += width;
inr -= width;
inp += width;
break;
}
}
nread += sum;
} else {
bcopy(inp, va_arg(ap, char *), width);
inr -= width;
inp += width;
nread += width;
nassigned++;
}
nconversions++;
break;
case CT_CCL:
/* scan a (nonempty) character class (sets NOSKIP) */
if (width == 0)
width = (size_t)~0; /* `infinity' */
/* take only those things in the class */
if (flags & SUPPRESS) {
n = 0;
while (ccltab[(unsigned char)*inp]) {
n++, inr--, inp++;
if (--width == 0)
break;
if (inr <= 0) {
if (n == 0)
goto input_failure;
break;
}
}
if (n == 0)
goto match_failure;
} else {
p0 = p = va_arg(ap, char *);
while (ccltab[(unsigned char)*inp]) {
inr--;
*p++ = *inp++;
if (--width == 0)
break;
if (inr <= 0) {
if (p == p0)
goto input_failure;
break;
}
}
n = p - p0;
if (n == 0)
goto match_failure;
*p = 0;
nassigned++;
}
nread += n;
nconversions++;
break;
case CT_STRING:
/* like CCL, but zero-length string OK, & no NOSKIP */
if (width == 0)
width = (size_t)~0;
if (flags & SUPPRESS) {
n = 0;
while (!isspace(*inp)) {
n++, inr--, inp++;
if (--width == 0)
break;
if (inr <= 0)
break;
}
nread += n;
} else {
p0 = p = va_arg(ap, char *);
while (!isspace(*inp)) {
inr--;
*p++ = *inp++;
if (--width == 0)
break;
if (inr <= 0)
break;
}
*p = 0;
nread += p - p0;
nassigned++;
}
nconversions++;
continue;
case CT_INT:
/* scan an integer as if by strtoq/strtouq */
#ifdef hardway
if (width == 0 || width > sizeof(buf) - 1)
width = sizeof(buf) - 1;
#else
/* size_t is unsigned, hence this optimisation */
if (--width > sizeof(buf) - 2)
width = sizeof(buf) - 2;
width++;
#endif
flags |= SIGNOK | NDIGITS | NZDIGITS;
for (p = buf; width; width--) {
c = *inp;
/*
* Switch on the character; `goto ok'
* if we accept it as a part of number.
*/
switch (c) {
/*
* The digit 0 is always legal, but is
* special. For %i conversions, if no
* digits (zero or nonzero) have been
* scanned (only signs), we will have
* base==0. In that case, we should set
* it to 8 and enable 0x prefixing.
* Also, if we have not scanned zero digits
* before this, do not turn off prefixing
* (someone else will turn it off if we
* have scanned any nonzero digits).
*/
case '0':
if (base == 0) {
base = 8;
flags |= PFXOK;
}
if (flags & NZDIGITS)
flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
else
flags &= ~(SIGNOK|PFXOK|NDIGITS);
goto ok;
/* 1 through 7 always legal */
case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
base = basefix[base];
flags &= ~(SIGNOK | PFXOK | NDIGITS);
goto ok;
/* digits 8 and 9 ok iff decimal or hex */
case '8': case '9':
base = basefix[base];
if (base <= 8)
break; /* not legal here */
flags &= ~(SIGNOK | PFXOK | NDIGITS);
goto ok;
/* letters ok iff hex */
case 'A': case 'B': case 'C':
case 'D': case 'E': case 'F':
case 'a': case 'b': case 'c':
case 'd': case 'e': case 'f':
/* no need to fix base here */
if (base <= 10)
break; /* not legal here */
flags &= ~(SIGNOK | PFXOK | NDIGITS);
goto ok;
/* sign ok only as first character */
case '+': case '-':
if (flags & SIGNOK) {
flags &= ~SIGNOK;
goto ok;
}
break;
/* x ok iff flag still set & 2nd char */
case 'x': case 'X':
if (flags & PFXOK && p == buf + 1) {
base = 16; /* if %i */
flags &= ~PFXOK;
goto ok;
}
break;
}
/*
* If we got here, c is not a legal character
* for a number. Stop accumulating digits.
*/
break;
ok:
/*
* c is legal: store it and look at the next.
*/
*p++ = c;
if (--inr > 0)
inp++;
else
break; /* end of input */
}
/*
* If we had only a sign, it is no good; push
* back the sign. If the number ends in `x',
* it was [sign] '0' 'x', so push back the x
* and treat it as [sign] '0'.
*/
if (flags & NDIGITS) {
if (p > buf) {
inp--;
inr++;
}
goto match_failure;
}
c = ((u_char *)p)[-1];
if (c == 'x' || c == 'X') {
--p;
inp--;
inr++;
}
if ((flags & SUPPRESS) == 0) {
u_quad_t res;
*p = 0;
res = (*ccfn)(buf, (const char **)NULL, base);
if (flags & POINTER)
*va_arg(ap, void **) =
(void *)(uintptr_t)res;
else if (flags & SHORT)
*va_arg(ap, short *) = res;
else if (flags & LONG)
*va_arg(ap, long *) = res;
else if (flags & QUAD)
*va_arg(ap, quad_t *) = res;
else
*va_arg(ap, int *) = res;
nassigned++;
}
nread += p - buf;
nconversions++;
break;
}
}
input_failure:
return (nconversions != 0 ? nassigned : -1);
match_failure:
return (nassigned);
}
/*
* Fill in the given table from the scanset at the given format
* (just after `['). Return a pointer to the character past the
* closing `]'. The table has a 1 wherever characters should be
* considered part of the scanset.
*/
static const u_char *
__sccl(char *tab, const u_char *fmt)
{
int c, n, v;
/* first `clear' the whole table */
c = *fmt++; /* first char hat => negated scanset */
if (c == '^') {
v = 1; /* default => accept */
c = *fmt++; /* get new first char */
} else
v = 0; /* default => reject */
/* XXX: Will not work if sizeof(tab*) > sizeof(char) */
for (n = 0; n < 256; n++)
tab[n] = v; /* memset(tab, v, 256) */
if (c == 0)
return (fmt - 1);/* format ended before closing ] */
/*
* Now set the entries corresponding to the actual scanset
* to the opposite of the above.
*
* The first character may be ']' (or '-') without being special;
* the last character may be '-'.
*/
v = 1 - v;
for (;;) {
tab[c] = v; /* take character c */
doswitch:
n = *fmt++; /* and examine the next */
switch (n) {
case 0: /* format ended too soon */
return (fmt - 1);
case '-':
/*
* A scanset of the form
* [01+-]
* is defined as `the digit 0, the digit 1,
* the character +, the character -', but
* the effect of a scanset such as
* [a-zA-Z0-9]
* is implementation defined. The V7 Unix
* scanf treats `a-z' as `the letters a through
* z', but treats `a-a' as `the letter a, the
* character -, and the letter a'.
*
* For compatibility, the `-' is not considerd
* to define a range if the character following
* it is either a close bracket (required by ANSI)
* or is not numerically greater than the character
* we just stored in the table (c).
*/
n = *fmt;
if (n == ']' || n < c) {
c = '-';
break; /* resume the for(;;) */
}
fmt++;
/* fill in the range */
do {
tab[++c] = v;
} while (c < n);
c = n;
/*
* Alas, the V7 Unix scanf also treats formats
* such as [a-c-e] as `the letters a through e'.
* This too is permitted by the standard....
*/
goto doswitch;
break;
case ']': /* end of scanset */
return (fmt);
default: /* just another character */
c = n;
break;
}
}
/* NOTREACHED */
}
/*
* Convert a string to an unsigned quad integer.
*
* Ignores `locale' stuff. Assumes that the upper and lower case
* alphabets and digits are each contiguous.
*/
u_quad_t
strtouq(const char *nptr, const char **endptr, int base)
{
const char *s = nptr;
u_quad_t acc;
unsigned char c;
u_quad_t qbase, cutoff;
int neg, any, cutlim;
/*
* See strtoq for comments as to the logic used.
*/
s = nptr;
do {
c = *s++;
} while (isspace(c));
if (c == '-') {
neg = 1;
c = *s++;
} else {
neg = 0;
if (c == '+')
c = *s++;
}
if ((base == 0 || base == 16) &&
c == '0' && (*s == 'x' || *s == 'X')) {
c = s[1];
s += 2;
base = 16;
}
if (base == 0)
base = c == '0' ? 8 : 10;
qbase = (unsigned)base;
cutoff = (u_quad_t)UQUAD_MAX / qbase;
cutlim = (u_quad_t)UQUAD_MAX % qbase;
for (acc = 0, any = 0;; c = *s++) {
if (!isascii(c))
break;
if (isdigit(c))
c -= '0';
else if (isalpha(c))
c -= isupper(c) ? 'A' - 10 : 'a' - 10;
else
break;
if (c >= base)
break;
if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
any = -1;
else {
any = 1;
acc *= qbase;
acc += c;
}
}
if (any < 0) {
acc = UQUAD_MAX;
} else if (neg)
acc = -acc;
if (endptr != 0)
*endptr = (const char *)(any ? s - 1 : nptr);
return (acc);
}
/*
* Convert a string to a quad integer.
*
* Ignores `locale' stuff. Assumes that the upper and lower case
* alphabets and digits are each contiguous.
*/
quad_t
strtoq(const char *nptr, const char **endptr, int base)
{
const char *s;
u_quad_t acc;
unsigned char c;
u_quad_t qbase, cutoff;
int neg, any, cutlim;
/*
* Skip white space and pick up leading +/- sign if any.
* If base is 0, allow 0x for hex and 0 for octal, else
* assume decimal; if base is already 16, allow 0x.
*/
s = nptr;
do {
c = *s++;
} while (isspace(c));
if (c == '-') {
neg = 1;
c = *s++;
} else {
neg = 0;
if (c == '+')
c = *s++;
}
if ((base == 0 || base == 16) &&
c == '0' && (*s == 'x' || *s == 'X')) {
c = s[1];
s += 2;
base = 16;
}
if (base == 0)
base = c == '0' ? 8 : 10;
/*
* Compute the cutoff value between legal numbers and illegal
* numbers. That is the largest legal value, divided by the
* base. An input number that is greater than this value, if
* followed by a legal input character, is too big. One that
* is equal to this value may be valid or not; the limit
* between valid and invalid numbers is then based on the last
* digit. For instance, if the range for quads is
* [-9223372036854775808..9223372036854775807] and the input base
* is 10, cutoff will be set to 922337203685477580 and cutlim to
* either 7 (neg==0) or 8 (neg==1), meaning that if we have
* accumulated a value > 922337203685477580, or equal but the
* next digit is > 7 (or 8), the number is too big, and we will
* return a range error.
*
* Set any if any `digits' consumed; make it negative to indicate
* overflow.
*/
qbase = (unsigned)base;
cutoff = neg ? (u_quad_t)-(QUAD_MIN + QUAD_MAX) + QUAD_MAX : QUAD_MAX;
cutlim = cutoff % qbase;
cutoff /= qbase;
for (acc = 0, any = 0;; c = *s++) {
if (!isascii(c))
break;
if (isdigit(c))
c -= '0';
else if (isalpha(c))
c -= isupper(c) ? 'A' - 10 : 'a' - 10;
else
break;
if (c >= base)
break;
if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
any = -1;
else {
any = 1;
acc *= qbase;
acc += c;
}
}
if (any < 0) {
acc = neg ? QUAD_MIN : QUAD_MAX;
} else if (neg)
acc = -acc;
if (endptr != 0)
*endptr = (const char *)(any ? s - 1 : nptr);
return (acc);
}
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