diff options
| -rw-r--r-- | 05/main.c | 12 | ||||
| -rw-r--r-- | 05/stdc_common.h | 26 | ||||
| -rw-r--r-- | 05/stdio.h | 435 | ||||
| -rw-r--r-- | 05/string.h | 7 |
4 files changed, 433 insertions, 47 deletions
@@ -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 { @@ -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 |