WebSVN – Kolibri OS – Blame – /programs/develop/ktcc/trunk/libc.obj/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	ch = vgetc(save, src);
9529	IgorA	175	if (ch == 'c' \|\| ch == 'C')
		176	base = 8;
		177	else if (ch == 'x' \|\| ch == 'X')
		178	base = 16;
		179	if (base == 10)
8687	turbocat	180	have_digits++;
		181	else
		182	{
9529	IgorA	183	char tch = vgetc(save, src);
		184	if ((base == 8 && isdigit(tch) && tch < '8') \|\|
		185	(base == 16 && isxdigit(tch)))
		186	ch = tch;
		187	else
		188	{
		189	have_digits++;
		190	//base = 10; // not required: zero is zero with any (base > 1)
		191	vungetc(save, tch, src);
		192	}
8687	turbocat	193	}
		194	}
		195	*digit = 0;
		196	for (;;)
		197	{
		198	// test ch is valid
		199	if ((isdigit(ch) && base == 10) \|\|
		200	(isdigit(ch) && base == 8 && ch < '8') \|\|
		201	(isxdigit(ch) && base == 16))
		202	{
		203	if (base == 16)
		204	{
9529	IgorA	205	if (ch <= '9') ch -= '0';
8687	turbocat	206	else
		207	if (ch <= 'F') ch = 10 + ch - 'A';
		208	else
		209	ch = 10 + ch - 'a';
		210	}
		211	else
		212	ch -= '0';
		213	digit = digit * base + ch;
		214	have_digits++;
		215	ch = vgetc(save, src);
		216	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		217	}
		218	else if (ch == EOF \|\| isspace(ch))
		219	break;
		220	else
		221	{
		222	vungetc(save, ch, src);
		223	break;
		224	}
		225	}
		226	digit = sign;
		227	if (have_digits)
		228	return 1;
		229	else
		230	return -2;
		231	}
		232
		233
		234
8718	turbocat	235	int format_scan(const void src, const char fmt, va_list argp, virtual_getc vgetc, virtual_ungetc vungetc)
8687	turbocat	236	{
8718	turbocat	237	int i;
		238	int length;
		239	int fmt1, fmt2; // width, precision
		240	size_t pos, posc;
		241	const char *fmtc; // first point to %, fmtc points to specifier
		242	int ch;
		243	int format_flag;
		244	int flag_long; // 2 = long double or long long int or wchar
		245	int *point_to_n = NULL, nread = 0;
		246	int flags; // parsed flags
		247	int save = 0;
		248	char *arg_str;
8687	turbocat	249	int *arg_int;
		250	long *arg_long;
		251	long long *arg_longlong;
		252	float *arg_float;
		253	double *arg_double;
		254	long double *arg_longdouble;
		255	long long digit;
		256	long double real;
		257
		258
		259	pos = 0;
		260	while(*fmt)
		261	{
		262	while (fmt && isspace(fmt)) fmt++; // skip paces in format str
		263
		264	if (*fmt != '%') // usual char
		265	{
		266	ch = vgetc(&save, src);
		267	if (ch != *fmt++) // char not match format
		268	{
		269	vungetc(&save, ch, src);
		270	break;
		271	}
		272	pos++;
		273	continue;
		274	}
		275
		276	if (*(fmt + 1) == '%') // %%
		277	{
		278	ch = vgetc(&save, src);
		279	if (ch != '%') // char not match format
		280	{
		281	vungetc(&save, ch, src);
		282	break;
		283	}
		284	pos++;
		285	fmt += 2;
		286	continue;
		287	}
		288	//checking to containg format in the string
		289	fmtc = fmt;
		290	posc = pos;
		291
		292	flags = 0;
		293	format_flag = 0;
		294	flag_long = 0; // 2 = long double or long long int or wchar
		295
		296	while(*fmtc != '\0' && !format_flag) // searching end of format
		297	{
		298	fmtc++; posc++;
		299	switch( *fmtc )
		300	{
		301	case 'a':
		302	format_flag = 1;
		303	flags \|= flag_unsigned;
		304	break;
		305	case 'c': case 'd': case 'i': case 'e': case 'f': case 'g': case 's': case 'n':
		306	format_flag = 1;
		307	break;
		308	case 'l':
		309	flag_long = flag_long ? 2 : 1; // ll.eq.L
		310	break;
		311	case 'L':
		312	flag_long = 2;
		313	break;
		314	case 'o': case 'u': case 'x': case 'p':
		315	format_flag = 1;
		316	flags \|= flag_unsigned;
		317	break;
		318	case '*': case '.': // just skip
		319	break;
		320	default:
		321	if(isdigit(*fmtc)) break;
		322	goto exit_me; // non format char found - user error
		323	}
		324	}
		325
		326	if (format_flag == 0)
		327	{
		328	goto exit_me; // format char not found - user error
		329	}
		330
		331	fmt1 = 0;
		332	fmt2 = 0;
		333	if (posc - pos > 1) // try to read width, precision
		334	{
		335	fmt++;
		336	for(i = pos + 1; i < posc; i++)
		337	{
		338	switch(*fmt)
		339	{
		340	case '0':
		341	if(fmt1 == 0 && (flags & flag_point) == 0) flags \|= flag_lead_zeros;
		342	case '1': case '2': case '3': case '4':
		343	case '5': case '6': case '7': case '8': case '9':
		344	if ((flags & flag_point) == 0)
		345	fmt1 = fmt1 * 10 + (*fmt -'0');
		346	else
		347	fmt2 = fmt2 * 10 + (*fmt -'0');
		348	break;
		349	case '*': // ignoring
		350	break;
		351	case '.':
		352	flags \|= flag_point;
		353	break;
		354	case 'l': case 'L': // valid chars - skip
		355	break;
		356	default: // must be error
		357	goto exit_me; // format char not found - user error
		358	}
		359	fmt++;
		360	}
		361	}
		362
		363	// do real work - format arguments values
		364	// skip input spaces
		365	do {
		366	ch = vgetc(&save, src);
		367	if (ch == EOF) goto exit_me;
		368	} while (isspace(ch));
		369
		370	switch(*fmtc)
		371	{
		372	case 'n':
		373	point_to_n = va_arg(argp, int*);
		374	vungetc(&save, ch, src);
		375	break;
		376	case 'c': // read width chars, ever spaces
		377	arg_str = va_arg(argp, char*);
		378	if (fmt1 == 0) length = 1;
		379	else length = fmt1;
		380	for (i = 0; i < length;)
		381	{
		382	*arg_str++ = ch; i++;
		383	ch = vgetc(&save, src);
		384	if (ch == EOF) break;
		385	}
		386	if (i < length) goto exit_me; // not enough chars
		387	break;
		388	case 's':
		389	arg_str = va_arg(argp, char*);
8718	turbocat	390	if (fmt1 == 0) length = 4095; // max string scan 4096
8687	turbocat	391	else length = fmt1;
		392	for (i = 0; i < length; i++)
		393	{
		394	*arg_str++ = ch;
		395	ch = vgetc(&save, src);
		396	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish string
		397	}
		398	*arg_str++ = '\0';
		399	break;
		400	case 'd': case 'i': case 'u':
		401	case 'o': case 'p': case 'x':
8718	turbocat	402	i = try_parse_int(&digit, ch, src, &save, vgetc, vungetc);
8687	turbocat	403	if (i < 0) goto exit_me;
		404
		405	if (flag_long == 0) { arg_int = va_arg(argp, int); arg_int = (int)digit; } else
		406	if (flag_long == 1) { arg_long = va_arg(argp, long); arg_long = (long)digit; } else
		407	if (flag_long == 2) { arg_longlong = va_arg(argp, long long); arg_longlong = digit; }
		408	break;
		409	case 'a': case 'A': case 'f': case 'F':
		410	case 'e': case 'E':
		411	case 'g': case 'G':
8718	turbocat	412	i = try_parse_real(&real, ch, src, &save, vgetc, vungetc);
8687	turbocat	413	if (i < 0) goto exit_me;
		414
		415	if (flag_long == 0) { arg_float = va_arg(argp, float); arg_float = (float)real; } else
		416	if (flag_long == 1) { arg_double = va_arg(argp, double); arg_double = (double)real; } else
		417	if (flag_long == 2) { arg_longdouble = va_arg(argp, long double); arg_longdouble = real; }
		418	break;
		419	}
		420
		421	fmt = fmtc + 1;
		422	nread++;
		423	}
		424	exit_me:
		425	if (point_to_n) *point_to_n = nread;
		426	return nread;
		427	}

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(root)/programs/develop/ktcc/trunk/libc.obj/source/stdio/format_scan.c – Rev 9529