mostly-standard scanf
This commit is contained in:
pommicket
parent
1ea9d85e3f
commit
f973ff8cb8
4 changed files with 433 additions and 47 deletions
435
05/stdio.h
435
05/stdio.h
|
|
@ -1582,12 +1582,22 @@ size_t fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream) {
|
|||
size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream) {
|
||||
size_t count;
|
||||
long n = 1;
|
||||
if (stream->eof) return 0;
|
||||
if (nmemb > 0xffffffffffffffff / size) {
|
||||
stream->err = 1;
|
||||
return 0;
|
||||
}
|
||||
if (size == 0 || nmemb == 0) return 0;
|
||||
|
||||
count = size * nmemb;
|
||||
|
||||
if (stream->has_ungetc) {
|
||||
*(char *)ptr = stream->ungetc;
|
||||
stream->has_ungetc = 0;
|
||||
ptr = (char *)ptr + 1;
|
||||
--count;
|
||||
}
|
||||
if (stream->eof) return 0;
|
||||
|
||||
while (count > 0) {
|
||||
n = read(stream->fd, ptr, count);
|
||||
if (n <= 0) break;
|
||||
|
|
@ -1741,33 +1751,13 @@ FILE *tmpfile(void) {
|
|||
return _FILE_from_fd(fd);
|
||||
}
|
||||
|
||||
// we don't buffer anything
|
||||
// we're allowed to do this: "The contents of the array at any time are indeterminate." C89 § 4.9.5.6
|
||||
void setbuf(FILE *stream, char *buf) {
|
||||
}
|
||||
|
||||
int setvbuf(FILE *stream, char *buf, int mode, size_t size) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
// @TODO
|
||||
int fscanf(FILE *stream, const char *format, ...);
|
||||
int sscanf(const char *s, const char *format, ...);
|
||||
int scanf(const char *format, ...);
|
||||
|
||||
int fgetc(FILE *stream) {
|
||||
unsigned char c;
|
||||
long n;
|
||||
if (stream->eof) return EOF;
|
||||
n = read(stream->fd, &c, 1);
|
||||
if (n > 0) return c;
|
||||
if (n < 0) {
|
||||
stream->err = 1;
|
||||
return EOF;
|
||||
}
|
||||
// n == 0
|
||||
stream->eof = 1;
|
||||
return EOF;
|
||||
n = fread(&c, 1, 1, stream);
|
||||
if (n != 1) return EOF;
|
||||
return c;
|
||||
}
|
||||
|
||||
#define getc(fp) fgetc(fp)
|
||||
|
|
@ -1778,13 +1768,8 @@ char *fgets(char *s, int n, FILE *stream) {
|
|||
if (stream->eof) return NULL;
|
||||
|
||||
while (p < end) {
|
||||
long n = read(stream->fd, p, 1);
|
||||
if (n < 0) {
|
||||
stream->err = 1;
|
||||
return NULL;
|
||||
}
|
||||
if (n == 0) {
|
||||
stream->eof = 1;
|
||||
size_t n = fread(p, 1, 1, stream);
|
||||
if (n != 1) {
|
||||
if (p == s) {
|
||||
// end of file reached, and no characters were read
|
||||
return NULL;
|
||||
|
|
@ -1841,9 +1826,11 @@ int puts(const char *s) {
|
|||
}
|
||||
|
||||
int ungetc(int c, FILE *stream) {
|
||||
/* @NONSTANDARD */
|
||||
fprintf(stderr, "ERROR: ungetc is not supported.\n");
|
||||
_Exit(-1);
|
||||
if (c == EOF || stream->has_ungetc) return EOF;
|
||||
stream->has_ungetc = 1;
|
||||
stream->ungetc = c;
|
||||
stream->eof = 0;
|
||||
return c;
|
||||
}
|
||||
|
||||
|
||||
|
|
@ -1902,6 +1889,386 @@ int ferror(FILE *stream) {
|
|||
return stream->err;
|
||||
}
|
||||
|
||||
// we don't buffer anything
|
||||
// we're allowed to do this: "The contents of the array at any time are indeterminate." C89 § 4.9.5.6
|
||||
void setbuf(FILE *stream, char *buf) {
|
||||
}
|
||||
|
||||
int setvbuf(FILE *stream, char *buf, int mode, size_t size) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
typedef int _VscanfNextChar(void *, long *);
|
||||
typedef int _VscanfPeekChar(void *);
|
||||
int _str_next_char(void *dat, long *pos) {
|
||||
const char **s = dat;
|
||||
int c = **s;
|
||||
if (c == '\0') return c;
|
||||
++*pos;
|
||||
++*s;
|
||||
return c;
|
||||
}
|
||||
int _file_next_char(void *dat, long *pos) {
|
||||
int c = getc(dat);
|
||||
if (c == EOF) return c;
|
||||
++*pos;
|
||||
return c;
|
||||
}
|
||||
int _str_peek_char(void *dat) {
|
||||
const char **s = dat;
|
||||
return **s;
|
||||
}
|
||||
int _file_peek_char(void *dat) {
|
||||
int c = getc(dat);
|
||||
ungetc(c, dat);
|
||||
return c;
|
||||
}
|
||||
|
||||
int _clamp_long_to_int(long x) {
|
||||
if (x < INT_MIN) return INT_MIN;
|
||||
if (x > INT_MAX) return INT_MAX;
|
||||
return x;
|
||||
}
|
||||
|
||||
short _clamp_long_to_short(long x) {
|
||||
if (x < SHRT_MIN) return SHRT_MIN;
|
||||
if (x > SHRT_MAX) return SHRT_MAX;
|
||||
return x;
|
||||
}
|
||||
|
||||
unsigned _clamp_ulong_to_uint(unsigned long x) {
|
||||
if (x > UINT_MAX) return UINT_MAX;
|
||||
return x;
|
||||
}
|
||||
|
||||
unsigned short _clamp_ulong_to_ushort(unsigned long x) {
|
||||
if (x > USHRT_MAX) return USHRT_MAX;
|
||||
return x;
|
||||
}
|
||||
|
||||
void _bad_scanf(void) {
|
||||
fprintf(stderr, "bad scanf format.\n");
|
||||
abort();
|
||||
}
|
||||
|
||||
char _parse_escape_sequence(char **p_str) {
|
||||
char *str = *p_str;
|
||||
if (*str == '\\') {
|
||||
++str;
|
||||
switch (*str) {
|
||||
case 'n': *p_str = str + 1; return '\n';
|
||||
case 'v': *p_str = str + 1; return '\v';
|
||||
case 't': *p_str = str + 1; return '\t';
|
||||
case 'a': *p_str = str + 1; return '\a';
|
||||
case 'f': *p_str = str + 1; return '\f';
|
||||
case 'r': *p_str = str + 1; return '\r';
|
||||
case 'b': *p_str = str + 1; return '\b';
|
||||
case 'x':
|
||||
++str;
|
||||
return (char)strtoul(str, p_str, 16);
|
||||
case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7': {
|
||||
int c = *str++ - '0';
|
||||
if (_isdigit_in_base(*str, 8)) c = (c << 3) + *str - '0', ++str;
|
||||
if (_isdigit_in_base(*str, 8)) c = (c << 3) + *str - '0', ++str;
|
||||
return c;
|
||||
} break;
|
||||
default: *p_str = str + 1; return *str;
|
||||
}
|
||||
} else {
|
||||
*p_str += 1;
|
||||
return *str;
|
||||
}
|
||||
}
|
||||
|
||||
int _vscanf(_VscanfNextChar *__next_char, _VscanfPeekChar *__peek_char, int terminator, void *data, const char *fmt, va_list args) {
|
||||
long pos = 0; // position in file/string (needed for %n)
|
||||
int assignments = 0;
|
||||
char number[128], *p_number;
|
||||
unsigned char charset[256];
|
||||
int i;
|
||||
|
||||
#define _next_char() (__next_char(data, &pos))
|
||||
#define _peek_char() (__peek_char(data))
|
||||
while (*fmt) {
|
||||
if (*fmt == '%') {
|
||||
int base = 10;
|
||||
int assign = 1;
|
||||
long field_width = LONG_MAX;
|
||||
int modifier = 0;
|
||||
char *end;
|
||||
|
||||
++fmt;
|
||||
if (*fmt == '*') assign = 0, ++fmt; // assignment suppression
|
||||
if (*fmt >= '0' && *fmt <= '9')
|
||||
field_width = strtol(fmt, &fmt, 10); // field width
|
||||
if (*fmt == 'l' || *fmt == 'L' || *fmt == 'h')
|
||||
modifier = *fmt, ++fmt;
|
||||
switch (*fmt) {
|
||||
case 'd': {
|
||||
while (isspace(_peek_char())) _next_char();
|
||||
// signed decimal integer
|
||||
++fmt;
|
||||
if (field_width > 100) field_width = 100; // max number length
|
||||
if (field_width == 0) goto vscanf_done; // number can't have size 0
|
||||
int c = _peek_char();
|
||||
p_number = number;
|
||||
if (c == '-' || c == '+') {
|
||||
if (field_width == 1) goto vscanf_done;
|
||||
*p_number++ = _next_char();
|
||||
}
|
||||
while ((p_number - number) < field_width && isdigit(_peek_char()))
|
||||
*p_number++ = _next_char();
|
||||
*p_number = 0;
|
||||
long value = strtol(number, &end, 10);
|
||||
if (end == number) goto vscanf_done; // bad number
|
||||
if (assign) {
|
||||
switch (modifier) {
|
||||
case 0: *va_arg(args, int*) = _clamp_long_to_int(value); break;
|
||||
case 'h': *va_arg(args, short*) = _clamp_long_to_short(value); break;
|
||||
case 'l': *va_arg(args, long*) = value; break;
|
||||
default: _bad_scanf(); break;
|
||||
}
|
||||
++assignments;
|
||||
}
|
||||
} break;
|
||||
case 'i': {
|
||||
while (isspace(_peek_char())) _next_char();
|
||||
// signed integer
|
||||
long value = 0;
|
||||
++fmt;
|
||||
if (field_width > 100) field_width = 100; // max number length
|
||||
if (field_width == 0) goto vscanf_done; // number can't have size 0
|
||||
int c = _peek_char();
|
||||
p_number = number;
|
||||
if (c == '-' || c == '+') {
|
||||
if (field_width == 1) goto vscanf_done;
|
||||
*p_number++ = _next_char();
|
||||
c = _peek_char();
|
||||
}
|
||||
if (c == '0') {
|
||||
*p_number++ = _next_char();
|
||||
if ((p_number - number) < field_width) {
|
||||
c = _peek_char();
|
||||
if (c == 'x') {
|
||||
if ((p_number - number) < field_width-1)
|
||||
*p_number++ = _next_char(), base = 16;
|
||||
else
|
||||
goto emit_value; // e.g. 0x... width field width 2
|
||||
} else {
|
||||
base = 8;
|
||||
}
|
||||
} else goto emit_value;
|
||||
}
|
||||
while ((p_number - number) < field_width && _isdigit_in_base(_peek_char(), base))
|
||||
*p_number++ = _next_char();
|
||||
*p_number = 0;
|
||||
value = strtol(number, &end, 0);
|
||||
if (end == number) goto vscanf_done; // bad number
|
||||
emit_value:
|
||||
if (assign) {
|
||||
switch (modifier) {
|
||||
case 0: *va_arg(args, int*) = _clamp_long_to_int(value); break;
|
||||
case 'h': *va_arg(args, short*) = _clamp_long_to_short(value); break;
|
||||
case 'l': *va_arg(args, long*) = value; break;
|
||||
default: _bad_scanf(); break;
|
||||
}
|
||||
++assignments;
|
||||
}
|
||||
} break;
|
||||
case 'o': base = 8; goto vscanf_unsigned;
|
||||
case 'u': goto vscanf_unsigned;
|
||||
case 'p': modifier = 'l', base = 16; goto vscanf_unsigned;
|
||||
case 'x': case 'X': base = 16; goto vscanf_unsigned;
|
||||
vscanf_unsigned:{
|
||||
while (isspace(_peek_char())) _next_char();
|
||||
// unsigned integers
|
||||
++fmt;
|
||||
if (field_width > 100) field_width = 100; // max number length
|
||||
if (field_width == 0) goto vscanf_done;
|
||||
int c = _peek_char();
|
||||
p_number = number;
|
||||
if (c == '+') *p_number++ = _next_char();
|
||||
while ((p_number - number) < field_width && _isdigit_in_base(_peek_char(), base))
|
||||
*p_number++ = _next_char();
|
||||
*p_number = 0;
|
||||
unsigned long value = strtoul(number, &end, base);
|
||||
if (end == number) goto vscanf_done; // bad number
|
||||
if (assign) {
|
||||
switch (modifier) {
|
||||
case 0: *va_arg(args, unsigned*) = _clamp_ulong_to_uint(value); break;
|
||||
case 'h': *va_arg(args, unsigned short*) = _clamp_ulong_to_ushort(value); break;
|
||||
case 'l': *va_arg(args, unsigned long*) = value; break;
|
||||
default: _bad_scanf(); break;
|
||||
}
|
||||
++assignments;
|
||||
}
|
||||
} break;
|
||||
case 'e':
|
||||
case 'f':
|
||||
case 'g':
|
||||
case 'E':
|
||||
case 'G': {
|
||||
while (isspace(_peek_char())) _next_char();
|
||||
// floats
|
||||
++fmt;
|
||||
if (field_width > 100) field_width = 100; // max number length
|
||||
if (field_width == 0) goto vscanf_done;
|
||||
int c = _peek_char();
|
||||
p_number = number;
|
||||
if (c == '-' || c == '+') {
|
||||
if (field_width == 1) goto vscanf_done;
|
||||
*p_number++ = _next_char();
|
||||
c = _peek_char();
|
||||
}
|
||||
if (c != '.' && !isdigit(c))
|
||||
goto vscanf_done;
|
||||
while ((p_number - number) < field_width && isdigit(_peek_char()))
|
||||
*p_number++ = _next_char();
|
||||
if ((p_number - number) < field_width && _peek_char() == '.') {
|
||||
*p_number++ = _next_char();
|
||||
while ((p_number - number) < field_width && isdigit(_peek_char()))
|
||||
*p_number++ = _next_char();
|
||||
}
|
||||
c = _peek_char();
|
||||
if ((p_number - number) < field_width && c == 'e' || c == 'E') {
|
||||
*p_number++ = _next_char();
|
||||
c = _peek_char();
|
||||
if ((p_number - number) < field_width && c == '+')
|
||||
*p_number++ = _next_char();
|
||||
else if ((p_number - number) < field_width && c == '-')
|
||||
*p_number++ = _next_char();
|
||||
|
||||
while ((p_number - number) < field_width && isdigit(_peek_char()))
|
||||
*p_number++ = _next_char();
|
||||
}
|
||||
double value = strtod(number, &end);
|
||||
if (end == number) goto vscanf_done; // bad number
|
||||
if (assign) {
|
||||
switch (modifier) {
|
||||
case 0: *va_arg(args, float*) = value; break;
|
||||
case 'l': case 'L': *va_arg(args, double*) = value; break;
|
||||
default: _bad_scanf(); break;
|
||||
}
|
||||
|
||||
++assignments;
|
||||
}
|
||||
} break;
|
||||
case 's': {
|
||||
while (isspace(_peek_char())) _next_char();
|
||||
// string of non-whitespace characters
|
||||
++fmt;
|
||||
char *str = assign ? va_arg(args, char*) : NULL, *p = str;
|
||||
for (i = 0; i < field_width && !isspace(_peek_char()); ++i) {
|
||||
int c = _next_char();
|
||||
if (c == terminator) break;
|
||||
if (p) *p++ = c;
|
||||
}
|
||||
if (i == 0) goto vscanf_done; // empty sequence
|
||||
if (p) {
|
||||
*p = 0;
|
||||
++assignments;
|
||||
}
|
||||
} break;
|
||||
case '[': {
|
||||
// string of characters in charset
|
||||
int complement = 0;
|
||||
++fmt;
|
||||
if (*fmt == '^') {
|
||||
complement = 1;
|
||||
++fmt;
|
||||
}
|
||||
memset(charset, complement, sizeof charset);
|
||||
do { // NB: this is a do-while loop and not a while loop, because []] matches strings of ]'s.
|
||||
charset[(unsigned char)_parse_escape_sequence(&fmt)] = !complement;
|
||||
} while (*fmt != ']');
|
||||
++fmt; // skip ]
|
||||
char *str = assign ? va_arg(args, char*) : NULL, *p = str;
|
||||
for (i = 0; i < field_width && charset[(unsigned char)_peek_char()]; ++i) {
|
||||
int c = _next_char();
|
||||
if (c == terminator) break;
|
||||
if (p) *p++ = c;
|
||||
}
|
||||
if (i == 0) goto vscanf_done; // empty sequence
|
||||
if (p) {
|
||||
*p = 0;
|
||||
++assignments;
|
||||
}
|
||||
} break;
|
||||
case 'c': {
|
||||
// string of characters
|
||||
++fmt;
|
||||
char *str = assign ? va_arg(args, char*) : NULL, *p = str;
|
||||
if (field_width == LONG_MAX) field_width = 1;
|
||||
for (i = 0; i < field_width; ++i) {
|
||||
int c = _next_char();
|
||||
if (c == terminator) break;
|
||||
if (p) *p++ = c;
|
||||
}
|
||||
if (i < field_width) goto vscanf_done; // end of file encountered
|
||||
if (p) {
|
||||
++assignments;
|
||||
}
|
||||
} break;
|
||||
case 'n':
|
||||
++fmt;
|
||||
switch (modifier) {
|
||||
case 0: *va_arg(args, int *) = pos; break;
|
||||
case 'h': *va_arg(args, short *) = pos; break;
|
||||
case 'l': *va_arg(args, long *) = pos; break;
|
||||
default: _bad_scanf(); break;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
_bad_scanf();
|
||||
break;
|
||||
}
|
||||
} else if (isspace(*fmt)) {
|
||||
// skip spaces in input
|
||||
++fmt;
|
||||
while (isspace(_peek_char())) _next_char();
|
||||
} else {
|
||||
if (_peek_char() == *fmt) {
|
||||
// format character matches input character
|
||||
++fmt;
|
||||
_next_char();
|
||||
} else {
|
||||
// format character doesn't match input character; stop parsing
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
vscanf_done:
|
||||
if (_peek_char() == terminator && assignments == 0) return EOF;
|
||||
return assignments;
|
||||
#undef _next_char
|
||||
#undef _peek_char
|
||||
}
|
||||
|
||||
int fscanf(FILE *stream, const char *format, ...) {
|
||||
va_list args;
|
||||
va_start(args, format);
|
||||
int ret = _vscanf(_file_next_char, _file_peek_char, EOF, stream, format, args);
|
||||
va_end(args);
|
||||
return ret;
|
||||
}
|
||||
|
||||
int sscanf(const char *s, const char *format, ...) {
|
||||
va_list args;
|
||||
va_start(args, format);
|
||||
int ret = _vscanf(_str_next_char, _str_peek_char, 0, &s, format, args);
|
||||
va_end(args);
|
||||
return ret;
|
||||
}
|
||||
|
||||
int scanf(const char *format, ...) {
|
||||
va_list args;
|
||||
va_start(args, format);
|
||||
int ret = _vscanf(_file_next_char, _file_peek_char, EOF, stdin, format, args);
|
||||
va_end(args);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
||||
void perror(const char *s); // @TODO
|
||||
|
||||
#undef STB_SPRINTF_MIN
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue