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-rw-r--r--05/main.c12
-rw-r--r--05/stdc_common.h26
-rw-r--r--05/stdio.h435
-rw-r--r--05/string.h7
4 files changed, 433 insertions, 47 deletions
diff --git a/05/main.c b/05/main.c
index 7b5789c..7ddf588 100644
--- a/05/main.c
+++ b/05/main.c
@@ -3,11 +3,13 @@
#include <string.h>
int main(void) {
- char *s = "1.35984534e135-e12hello";
- char *end;
- _Float f = _powers_of_10[-307];
- printf("%.15g\n",strtod(s, &end));
- printf("%s\n",end);
+ int count; float quant; char units[21], item[21];
+ while (!feof(stdin) && !ferror(stdin)) {
+ count = fscanf(stdin, "%f%20s of %20s",
+ &quant, units, item);
+ fscanf(stdin,"%*[^\n]");
+ printf("%d %g %s %s\n", count, quant, units, item);
+ }
return 0;
}
diff --git a/05/stdc_common.h b/05/stdc_common.h
index 22c5a42..c40fd3d 100644
--- a/05/stdc_common.h
+++ b/05/stdc_common.h
@@ -143,6 +143,8 @@ typedef struct {
int fd;
unsigned char eof;
unsigned char err;
+ unsigned char has_ungetc;
+ char ungetc; // character which was pushed by ungetc()
} FILE;
int errno;
@@ -213,6 +215,28 @@ int isspace(int c) {
return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v';
}
+int isdigit(int c) {
+ return c >= '0' && c <= '9';
+}
+
+int _isdigit_in_base(int c, int base) {
+ if (c >= '0' && c <= '9') {
+ return c - '0' < base;
+ } else if (c >= 'a' && c <= 'z') {
+ return c - 'a' + 10 < base;
+ } else if (c >= 'A' && c <= 'Z') {
+ return c - 'A' + 10 < base;
+ }
+ return 0;
+}
+
+void *memset(void *s, int c, size_t n) {
+ char *p = s, *end = p + n;
+ while (p < end)
+ *p++ = c;
+ return s;
+}
+
unsigned long strtoul(const char *nptr, char **endptr, int base) {
unsigned long value = 0, newvalue;
int overflow = 0;
@@ -277,7 +301,7 @@ long strtol(const char *nptr, char **endptr, int base) {
if (sign > 0) {
if (mag > LONG_MAX) {
errno = ERANGE;
- return LONG_MIN;
+ return LONG_MAX;
}
return (long)mag;
} else {
diff --git a/05/stdio.h b/05/stdio.h
index 4ca0307..8320b4b 100644
--- a/05/stdio.h
+++ b/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
diff --git a/05/string.h b/05/string.h
index 1ea2a91..e585f6b 100644
--- a/05/string.h
+++ b/05/string.h
@@ -3,13 +3,6 @@
#include <stdc_common.h>
-void *memset(void *s, int c, size_t n) {
- char *p = s, *end = p + n;
- while (p < end)
- *p++ = c;
- return s;
-}
-
#endif // _STRING_H
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 07:08:44 +0000