static inline void
SetBit(unsigned long *bitmap, unsigned int bit) {
bitmap[bit/LongBit()] |= 1UL << (bit%LongBit());
}
static inline int
TestBit(unsigned long *bitmap, unsigned int bit) {
return static_cast<int>(bitmap[bit/LongBit()] >> (bit%LongBit())) & 1;
}
int vfscanf(FILE* stream, const char *format, va_list ap)
{
const char *p = format;
char ch;
int q = 0;
uintmax_t val = 0;
int rank = RANK_INT; // Default rank
unsigned int width = UINT_MAX;
int base;
int flags = 0;
enum {
ST_NORMAL, // Ground state
ST_FLAGS, // Special flags
ST_WIDTH, // Field width
ST_MODIFIERS, // Length or conversion modifiers
ST_MATCH_INIT, // Initial state of %[ sequence
ST_MATCH, // Main state of %[ sequence
ST_MATCH_RANGE, // After - in a %[ sequence
} state = ST_NORMAL;
char *oarg, *sarg = NULL; // %s %c or %[ string argument
enum Bail bail = BAIL_NONE;
int sign;
int converted = 0; // Successful conversions
unsigned long matchmap[((1 << CHAR_BIT)+(LongBit()-1))/LongBit()];
int matchinv = 0; // Is match map inverted?
unsigned char range_start = 0;
off_t start_off = ftell(stream);
// Skip leading spaces
SkipSpace(stream);
while ((ch = *p++) && !bail) {
switch (state) {
case ST_NORMAL:
if (ch == '%') {
state = ST_FLAGS;
flags = 0; rank = RANK_INT; width = UINT_MAX;
} else if (isspace(static_cast<unsigned char>(ch))) {
SkipSpace(stream);
} else {
if (fgetc(stream) != ch)
bail = BAIL_ERR; // Match failure
}
break;
case ST_FLAGS:
switch (ch) {
case '*':
flags |= FL_SPLAT;
break;
case '0' ... '9':
width = (ch-'0');
state = ST_WIDTH;
flags |= FL_WIDTH;
break;
default:
state = ST_MODIFIERS;
p--; // Process this character again
break;
}
break;
case ST_WIDTH:
if (ch >= '0' && ch <= '9') {
width = width*10+(ch-'0');
} else {
state = ST_MODIFIERS;
p--; // Process this character again
}
break;
case ST_MODIFIERS:
switch (ch) {
// Length modifiers - nonterminal sequences
case 'h':
rank--; // Shorter rank
break;
case 'l':
rank++; // Longer rank
break;
case 'j':
rank = kIntMaxRank;
break;
case 'z':
rank = kSizeTRank;
break;
case 't':
rank = kPtrDiffRank;
break;
case 'L':
case 'q':
rank = RANK_LONGLONG; // long double/long long
break;
default:
// Output modifiers - terminal sequences
state = ST_NORMAL; // Next state will be normal
if (rank < kMinRank) // Canonicalize rank
rank = kMinRank;
else if (rank > kMaxRank)
rank = kMaxRank;
switch (ch) {
case 'P': // Upper case pointer
case 'p': // Pointer
rank = RANK_PTR;
base = 0; sign = 0;
goto scan_int;
case 'i': // Base-independent integer
base = 0; sign = 1;
goto scan_int;
case 'd': // Decimal integer
base = 10; sign = 1;
goto scan_int;
case 'o': // Octal integer
base = 8; sign = 0;
goto scan_int;
case 'u': // Unsigned decimal integer
base = 10; sign = 0;
goto scan_int;
case 'x': // Hexadecimal integer
case 'X':
base = 16; sign = 0;
goto scan_int;
case 'n': // Number of characters consumed
val = ftell(stream) - start_off;
goto set_integer;
scan_int:
q = SkipSpace(stream);
if ( q <= 0 ) {
bail = BAIL_EOF;
break;
}
val = streamtoumax(stream, base);
converted++;
// fall through
set_integer:
if (!(flags & FL_SPLAT)) {
switch(rank) {
case RANK_CHAR:
*va_arg(ap, unsigned char *)
= static_cast<unsigned char>(val);
break;
case RANK_SHORT:
*va_arg(ap, unsigned short *)
= static_cast<unsigned short>(val);
break;
case RANK_INT:
*va_arg(ap, unsigned int *)
= static_cast<unsigned int>(val);
break;
case RANK_LONG:
*va_arg(ap, unsigned long *)
= static_cast<unsigned long>(val);
break;
case RANK_LONGLONG:
*va_arg(ap, unsigned long long *)
= static_cast<unsigned long long>(val);
break;
case RANK_PTR:
*va_arg(ap, void **)
= reinterpret_cast<void *>(static_cast<uintptr_t>(val));
break;
}
}
break;
case 'f': // Preliminary float value parsing
case 'g':
case 'G':
case 'e':
case 'E':
q = SkipSpace(stream);
if (q <= 0) {
bail = BAIL_EOF;
break;
}
double fval = streamtofloat(stream);
switch(rank) {
case RANK_INT:
*va_arg(ap, float *) = static_cast<float>(fval);
break;
case RANK_LONG:
*va_arg(ap, double *) = static_cast<double>(fval);
break;
}
converted++;
break;
case 'c': // Character
width = (flags & FL_WIDTH) ? width : 1; // Default width == 1
sarg = va_arg(ap, char *);
while (width--) {
if ((q = fgetc(stream)) <= 0) {
bail = BAIL_EOF;
break;
}
*sarg++ = q;
}
if (!bail)
converted++;
break;
case 's': // String
{
char *sp;
sp = sarg = va_arg(ap, char *);
while (width--) {
q = fgetc(stream);
if (isspace(static_cast<unsigned char>(q)) || q <= 0) {
ungetc(q, stream);
break;
}
*sp++ = q;
}
if (sarg != sp) {
*sp = '\0'; // Terminate output
converted++;
} else {
bail = BAIL_EOF;
}
}
break;
case '[': // Character range
sarg = va_arg(ap, char *);
state = ST_MATCH_INIT;
matchinv = 0;
memset(matchmap, 0, sizeof matchmap);
break;
case '%': // %% sequence
if (fgetc(stream) != '%' )
bail = BAIL_ERR;
break;
default: // Anything else
bail = BAIL_ERR; // Unknown sequence
break;
}
}
break;
case ST_MATCH_INIT: // Initial state for %[ match
if (ch == '^' && !(flags & FL_INV)) {
matchinv = 1;
} else {
SetBit(matchmap, static_cast<unsigned char>(ch));
state = ST_MATCH;
}
break;
case ST_MATCH: // Main state for %[ match
if (ch == ']') {
goto match_run;
} else if (ch == '-') {
range_start = static_cast<unsigned char>(ch);
state = ST_MATCH_RANGE;
} else {
SetBit(matchmap, static_cast<unsigned char>(ch));
}
break;
case ST_MATCH_RANGE: // %[ match after -
if (ch == ']') {
SetBit(matchmap, static_cast<unsigned char>('-'));
goto match_run;
} else {
int i;
for (i = range_start ; i < (static_cast<unsigned char>(ch)) ; i++)
SetBit(matchmap, i);
state = ST_MATCH;
}
break;
match_run: // Match expression finished
char* oarg = sarg;
while (width) {
q = fgetc(stream);
unsigned char qc = static_cast<unsigned char>(q);
if (q <= 0 || !(TestBit(matchmap, qc)^matchinv)) {
ungetc(q, stream);
break;
}
*sarg++ = q;
}
if (oarg != sarg) {
*sarg = '\0';
converted++;
} else {
bail = (q <= 0) ? BAIL_EOF : BAIL_ERR;
}
break;
}
}
if (bail == BAIL_EOF && !converted)
converted = -1; // Return EOF (-1)
return converted;
}
