WebSVN – Kolibri OS – Blame – /programs/develop/libraries/kolibri-libc/source/stdio/format_scan.c

Rev	Author	Line No.	Line
8687	turbocat	1	/*
		2	function for format read from any source
		3
		4	Siemargl formats as http://www.cplusplus.com/reference/cstdio/scanf/, no wchar though
		5	http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap05.html is used too
		6
		7	todo:
		8	[characters], [^characters]
		9	-%n nothing scanned, filled only if good result
		10	-%d, i, u, o, x, p read similar - detect base by prefix 0 or 0x
		11	-%a
		12	-can overflow unsigned as signed
		13	-radix point always '.', no LOCALEs
		14	*/
		15
8718	turbocat	16
8687	turbocat	17	#include
		18	#include
		19	#include
		20	#include
		21
8718	turbocat	22	typedef int (virtual_getc)(void sp, const void *obj);
		23	typedef void (virtual_ungetc)(void sp, int c, const void *obj);
		24
		25	enum flags_t
		26	{
		27	flag_unsigned = 0x02,
		28	flag_register = 0x04,
		29	flag_plus = 0x08,
		30	flag_left_just = 0x10,
		31	flag_lead_zeros = 0x20,
		32	flag_space_plus = 0x40,
		33	flag_hash_sign = 0x80,
		34	flag_point = 0x100
		35	};
		36
		37	int try_parse_real(long double real, int ch, const void src, void *save, virtual_getc vgetc, virtual_ungetc vungetc)
8687	turbocat	38	// returns 1 if OK, -1 == EOF, -2 parse broken
		39	{
		40	int sign = 1, have_digits = 0;
		41	long long div;
		42
		43	if (ch == '+')
		44	{
		45	ch = vgetc(save, src);
		46	if (ch == EOF) return EOF;
		47	} else
		48	if (ch == '-')
		49	{
		50	sign = -1;
		51	ch = vgetc(save, src);
		52	if (ch == EOF) return EOF;
		53	};
		54	*real = 0.0;
		55	for (;;) // mantissa before point
		56	{
		57	// test ch is valid
		58	if (isdigit(ch))
		59	{
		60	real = real * 10 + ch - '0';
		61	have_digits++;
		62	ch = vgetc(save, src);
		63	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		64	} else
		65	if (ch == '.' \|\| ch == 'E' \|\| ch == 'e')
		66	{
		67	break; // ok
		68	}
		69	else
		70	{
		71	vungetc(save, ch, src);
		72	break;
		73	}
		74	}
		75	if (ch != '.' && ch != 'E' && ch != 'e') // ok, just integer part
		76	{
		77	real = sign;
		78	if (have_digits)
		79	return 1;
		80	else
		81	return -2;
		82	}
		83
		84	if(ch == '.')
		85	{
		86	ch = vgetc(save, src);
		87	div = 10; // use as divisor
		88	for (;;) // mantissa after point
		89	{
		90	// test ch is valid
		91	if (isdigit(ch))
		92	{
		93	*real += (double)(ch - '0') / div;
		94	div *= 10;
		95	have_digits++;
		96	ch = vgetc(save, src);
		97	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		98	} else
		99	if (ch == 'E' \|\| ch == 'e')
		100	{
		101	break; // ok
		102	}
		103	else
		104	{
		105	vungetc(save, ch, src);
		106	break;
		107	}
		108	}
		109	if (ch != 'E' && ch != 'e') // ok, real as XX.YY
		110	{
		111	real = sign;
		112	if (have_digits)
		113	return 1;
		114	else
		115	return -2;
		116	}
		117	}
		118
		119	ch = vgetc(save, src);
		120	real = sign;
		121	// exponent
		122	sign = 1;
		123	if (ch == '+')
		124	{
		125	ch = vgetc(save, src);
		126	if (ch == EOF) return EOF;
		127	} else
		128	if (ch == '-')
		129	{
		130	sign = -1;
		131	ch = vgetc(save, src);
		132	if (ch == EOF) return EOF;
		133	};
		134	div = 0;
		135	for (;;)
		136	{
		137	// test ch is valid
		138	if (isdigit(ch))
		139	{
		140	div = div * 10 + ch - '0';
		141	ch = vgetc(save, src);
		142	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		143	}
		144	else
		145	{
		146	vungetc(save, ch, src);
		147	break;
		148	}
		149	}
		150	div *= sign;
8718	turbocat	151	real = pow(10, div);
8687	turbocat	152
		153	return 1;
		154	}
		155
8718	turbocat	156	int try_parse_int(long long digit, int ch, const void src, void *save, virtual_getc vgetc, virtual_ungetc vungetc)
8687	turbocat	157	{
		158	int sign = 1, base = 10, have_digits = 0;
		159
		160	if (ch == '+')
		161	{
		162	ch = vgetc(save, src);
		163	if (ch == EOF) return EOF;
		164	} else
		165	if (ch == '-')
		166	{
		167	sign = -1;
		168	ch = vgetc(save, src);
		169	if (ch == EOF) return EOF;
		170	};
		171
		172	if (ch == '0') // octal or hex, read next
		173	{
		174	base = 8;
		175	ch = vgetc(save, src);
		176	if (ch == EOF \|\| isspace(ch))
		177	have_digits++;
		178	else
		179	if (ch == 'x' \|\| ch == 'X')
		180	{
		181	base = 16;
		182	ch = vgetc(save, src);
		183	if (ch == EOF) return EOF;
		184	}
		185	}
		186	*digit = 0;
		187	for (;;)
		188	{
		189	// test ch is valid
		190	if ((isdigit(ch) && base == 10) \|\|
		191	(isdigit(ch) && base == 8 && ch < '8') \|\|
		192	(isxdigit(ch) && base == 16))
		193	{
		194	if (base == 16)
		195	{
		196	if (ch <= '9') ch-= '0';
		197	else
		198	if (ch <= 'F') ch = 10 + ch - 'A';
		199	else
		200	ch = 10 + ch - 'a';
		201	}
		202	else
		203	ch -= '0';
		204	digit = digit * base + ch;
		205	have_digits++;
		206	ch = vgetc(save, src);
		207	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		208	}
		209	else if (ch == EOF \|\| isspace(ch))
		210	break;
		211	else
		212	{
		213	vungetc(save, ch, src);
		214	break;
		215	}
		216	}
		217	digit = sign;
		218	if (have_digits)
		219	return 1;
		220	else
		221	return -2;
		222	}
		223
		224
		225
8718	turbocat	226	int format_scan(const void src, const char fmt, va_list argp, virtual_getc vgetc, virtual_ungetc vungetc)
8687	turbocat	227	{
8718	turbocat	228	int i;
		229	int length;
		230	int fmt1, fmt2; // width, precision
		231	size_t pos, posc;
		232	const char *fmtc; // first point to %, fmtc points to specifier
		233	int ch;
		234	int format_flag;
		235	int flag_long; // 2 = long double or long long int or wchar
		236	int *point_to_n = NULL, nread = 0;
		237	int flags; // parsed flags
		238	int save = 0;
		239	char *arg_str;
8687	turbocat	240	int *arg_int;
		241	long *arg_long;
		242	long long *arg_longlong;
		243	float *arg_float;
		244	double *arg_double;
		245	long double *arg_longdouble;
		246	long long digit;
		247	long double real;
		248
		249
		250	pos = 0;
		251	while(*fmt)
		252	{
		253	while (fmt && isspace(fmt)) fmt++; // skip paces in format str
		254
		255	if (*fmt != '%') // usual char
		256	{
		257	ch = vgetc(&save, src);
		258	if (ch != *fmt++) // char not match format
		259	{
		260	vungetc(&save, ch, src);
		261	break;
		262	}
		263	pos++;
		264	continue;
		265	}
		266
		267	if (*(fmt + 1) == '%') // %%
		268	{
		269	ch = vgetc(&save, src);
		270	if (ch != '%') // char not match format
		271	{
		272	vungetc(&save, ch, src);
		273	break;
		274	}
		275	pos++;
		276	fmt += 2;
		277	continue;
		278	}
		279	//checking to containg format in the string
		280	fmtc = fmt;
		281	posc = pos;
		282
		283	flags = 0;
		284	format_flag = 0;
		285	flag_long = 0; // 2 = long double or long long int or wchar
		286
		287	while(*fmtc != '\0' && !format_flag) // searching end of format
		288	{
		289	fmtc++; posc++;
		290	switch( *fmtc )
		291	{
		292	case 'a':
		293	format_flag = 1;
		294	flags \|= flag_unsigned;
		295	break;
		296	case 'c': case 'd': case 'i': case 'e': case 'f': case 'g': case 's': case 'n':
		297	format_flag = 1;
		298	break;
		299	case 'l':
		300	flag_long = flag_long ? 2 : 1; // ll.eq.L
		301	break;
		302	case 'L':
		303	flag_long = 2;
		304	break;
		305	case 'o': case 'u': case 'x': case 'p':
		306	format_flag = 1;
		307	flags \|= flag_unsigned;
		308	break;
		309	case '*': case '.': // just skip
		310	break;
		311	default:
		312	if(isdigit(*fmtc)) break;
		313	goto exit_me; // non format char found - user error
		314	}
		315	}
		316
		317	if (format_flag == 0)
		318	{
		319	goto exit_me; // format char not found - user error
		320	}
		321
		322	fmt1 = 0;
		323	fmt2 = 0;
		324	if (posc - pos > 1) // try to read width, precision
		325	{
		326	fmt++;
		327	for(i = pos + 1; i < posc; i++)
		328	{
		329	switch(*fmt)
		330	{
		331	case '0':
		332	if(fmt1 == 0 && (flags & flag_point) == 0) flags \|= flag_lead_zeros;
		333	case '1': case '2': case '3': case '4':
		334	case '5': case '6': case '7': case '8': case '9':
		335	if ((flags & flag_point) == 0)
		336	fmt1 = fmt1 * 10 + (*fmt -'0');
		337	else
		338	fmt2 = fmt2 * 10 + (*fmt -'0');
		339	break;
		340	case '*': // ignoring
		341	break;
		342	case '.':
		343	flags \|= flag_point;
		344	break;
		345	case 'l': case 'L': // valid chars - skip
		346	break;
		347	default: // must be error
		348	goto exit_me; // format char not found - user error
		349	}
		350	fmt++;
		351	}
		352	}
		353
		354	// do real work - format arguments values
		355	// skip input spaces
		356	do {
		357	ch = vgetc(&save, src);
		358	if (ch == EOF) goto exit_me;
		359	} while (isspace(ch));
		360
		361	switch(*fmtc)
		362	{
		363	case 'n':
		364	point_to_n = va_arg(argp, int*);
		365	vungetc(&save, ch, src);
		366	break;
		367	case 'c': // read width chars, ever spaces
		368	arg_str = va_arg(argp, char*);
		369	if (fmt1 == 0) length = 1;
		370	else length = fmt1;
		371	for (i = 0; i < length;)
		372	{
		373	*arg_str++ = ch; i++;
		374	ch = vgetc(&save, src);
		375	if (ch == EOF) break;
		376	}
		377	if (i < length) goto exit_me; // not enough chars
		378	break;
		379	case 's':
		380	arg_str = va_arg(argp, char*);
8718	turbocat	381	if (fmt1 == 0) length = 4095; // max string scan 4096
8687	turbocat	382	else length = fmt1;
		383	for (i = 0; i < length; i++)
		384	{
		385	*arg_str++ = ch;
		386	ch = vgetc(&save, src);
		387	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish string
		388	}
		389	*arg_str++ = '\0';
		390	break;
		391	case 'd': case 'i': case 'u':
		392	case 'o': case 'p': case 'x':
8718	turbocat	393	i = try_parse_int(&digit, ch, src, &save, vgetc, vungetc);
8687	turbocat	394	if (i < 0) goto exit_me;
		395
		396	if (flag_long == 0) { arg_int = va_arg(argp, int); arg_int = (int)digit; } else
		397	if (flag_long == 1) { arg_long = va_arg(argp, long); arg_long = (long)digit; } else
		398	if (flag_long == 2) { arg_longlong = va_arg(argp, long long); arg_longlong = digit; }
		399	break;
		400	case 'a': case 'A': case 'f': case 'F':
		401	case 'e': case 'E':
		402	case 'g': case 'G':
8718	turbocat	403	i = try_parse_real(&real, ch, src, &save, vgetc, vungetc);
8687	turbocat	404	if (i < 0) goto exit_me;
		405
		406	if (flag_long == 0) { arg_float = va_arg(argp, float); arg_float = (float)real; } else
		407	if (flag_long == 1) { arg_double = va_arg(argp, double); arg_double = (double)real; } else
		408	if (flag_long == 2) { arg_longdouble = va_arg(argp, long double); arg_longdouble = real; }
		409	break;
		410	}
		411
		412	fmt = fmtc + 1;
		413	nread++;
		414	}
		415	exit_me:
		416	if (point_to_n) *point_to_n = nread;
		417	return nread;
		418	}

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(root)/programs/develop/libraries/kolibri-libc/source/stdio/format_scan.c – Rev 8718