WebSVN – Kolibri OS – Blame – /programs/develop/ktcc/trunk/libc/stdio/format_scan.c

Rev	Author	Line No.	Line
6431	siemargl	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
		16
		17	#include
		18	#include
		19	#include
		20	#include
6432	siemargl	21	typedef int (virtual_getc)(void sp, const void *obj);
		22	typedef void (virtual_ungetc)(void sp, int c, const void *obj);
6431	siemargl	23
		24	enum flags_t
		25	{
		26	flag_unsigned = 0x02,
		27	flag_register = 0x04,
		28	flag_plus = 0x08,
		29	flag_left_just = 0x10,
		30	flag_lead_zeros = 0x20,
		31	flag_space_plus = 0x40,
		32	flag_hash_sign = 0x80,
		33	flag_point = 0x100
		34	};
		35
		36	int try_parse_real(long double real, int ch, const void src, void *save, virtual_getc vgetc, virtual_ungetc vungetc)
		37	// returns 1 if OK, -1 == EOF, -2 parse broken
		38	{
		39	int sign = 1, have_digits = 0;
		40	long long div;
		41
		42	if (ch == '+')
		43	{
		44	ch = vgetc(save, src);
		45	if (ch == EOF) return EOF;
		46	} else
		47	if (ch == '-')
		48	{
		49	sign = -1;
		50	ch = vgetc(save, src);
		51	if (ch == EOF) return EOF;
		52	};
		53	*real = 0.0;
		54	for (;;) // mantissa before point
		55	{
		56	// test ch is valid
		57	if (isdigit(ch))
		58	{
		59	real = real * 10 + ch - '0';
		60	have_digits++;
		61	ch = vgetc(save, src);
		62	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		63	} else
		64	if (ch == '.' \|\| ch == 'E' \|\| ch == 'e')
		65	{
		66	break; // ok
		67	}
		68	else
		69	{
		70	vungetc(save, ch, src);
		71	break;
		72	}
		73	}
		74	if (ch != '.' && ch != 'E' && ch != 'e') // ok, just integer part
		75	{
		76	real = sign;
		77	if (have_digits)
		78	return 1;
		79	else
		80	return -2;
		81	}
		82
		83	if(ch == '.')
		84	{
		85	ch = vgetc(save, src);
		86	div = 10; // use as divisor
		87	for (;;) // mantissa after point
		88	{
		89	// test ch is valid
		90	if (isdigit(ch))
		91	{
		92	*real += (double)(ch - '0') / div;
		93	div *= 10;
		94	have_digits++;
		95	ch = vgetc(save, src);
		96	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		97	} else
		98	if (ch == 'E' \|\| ch == 'e')
		99	{
		100	break; // ok
		101	}
		102	else
		103	{
		104	vungetc(save, ch, src);
		105	break;
		106	}
		107	}
		108	if (ch != 'E' && ch != 'e') // ok, real as XX.YY
		109	{
		110	real = sign;
		111	if (have_digits)
		112	return 1;
		113	else
		114	return -2;
		115	}
		116	}
		117
		118	ch = vgetc(save, src);
		119	real = sign;
		120	// exponent
		121	sign = 1;
		122	if (ch == '+')
		123	{
		124	ch = vgetc(save, src);
		125	if (ch == EOF) return EOF;
		126	} else
		127	if (ch == '-')
		128	{
		129	sign = -1;
		130	ch = vgetc(save, src);
		131	if (ch == EOF) return EOF;
		132	};
		133	div = 0;
		134	for (;;)
		135	{
		136	// test ch is valid
		137	if (isdigit(ch))
		138	{
		139	div = div * 10 + ch - '0';
		140	ch = vgetc(save, src);
		141	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		142	}
		143	else
		144	{
		145	vungetc(save, ch, src);
		146	break;
		147	}
		148	}
		149	div *= sign;
		150	real = pow(10, div);
		151
		152	return 1;
		153	}
		154
		155	int try_parse_int(long long digit, int ch, const void src, void *save, virtual_getc vgetc, virtual_ungetc vungetc)
		156	{
		157	int sign = 1, base = 10, have_digits = 0;
		158
		159	if (ch == '+')
		160	{
		161	ch = vgetc(save, src);
		162	if (ch == EOF) return EOF;
		163	} else
		164	if (ch == '-')
		165	{
		166	sign = -1;
		167	ch = vgetc(save, src);
		168	if (ch == EOF) return EOF;
		169	};
		170
		171	if (ch == '0') // octal or hex, read next
		172	{
		173	base = 8;
		174	ch = vgetc(save, src);
6432	siemargl	175	if (ch == EOF \|\| isspace(ch))
		176	have_digits++;
		177	else
6431	siemargl	178	if (ch == 'x' \|\| ch == 'X')
		179	{
		180	base = 16;
		181	ch = vgetc(save, src);
		182	if (ch == EOF) return EOF;
		183	}
		184	}
		185	*digit = 0;
		186	for (;;)
		187	{
		188	// test ch is valid
		189	if ((isdigit(ch) && base == 10) \|\|
		190	(isdigit(ch) && base == 8 && ch < '8') \|\|
		191	(isxdigit(ch) && base == 16))
		192	{
		193	if (base == 16)
		194	{
		195	if (ch <= '9') ch-= '0';
		196	else
		197	if (ch <= 'F') ch = 10 + ch - 'A';
		198	else
		199	ch = 10 + ch - 'a';
		200	}
		201	else
		202	ch -= '0';
		203	digit = digit * base + ch;
		204	have_digits++;
		205	ch = vgetc(save, src);
		206	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish num
		207	}
6432	siemargl	208	else if (ch == EOF \|\| isspace(ch))
		209	break;
6431	siemargl	210	else
		211	{
		212	vungetc(save, ch, src);
		213	break;
		214	}
		215	}
		216	digit = sign;
		217	if (have_digits)
		218	return 1;
		219	else
		220	return -2;
		221	}
		222
		223
		224
		225	int format_scan(const void src, const char fmt, va_list argp, virtual_getc vgetc, virtual_ungetc vungetc)
		226	{
		227	int i;
		228	int length;
		229	int fmt1, fmt2; // width, precision
		230	size_t pos, posc;
		231	const char *fmtc; // first point to %, fmtc points to specifier
		232	int ch;
		233	int format_flag;
		234	int flag_long; // 2 = long double or long long int or wchar
		235	int *point_to_n = NULL, nread = 0;
		236	int flags; // parsed flags
		237	int save = 0;
		238	char *arg_str;
		239	int *arg_int;
		240	long *arg_long;
		241	long long *arg_longlong;
		242	float *arg_float;
		243	double *arg_double;
		244	long double *arg_longdouble;
		245	long long digit;
		246	long double real;
		247
		248
		249	pos = 0;
		250	while(*fmt)
		251	{
		252	while (fmt && isspace(fmt)) fmt++; // skip paces in format str
		253
		254	if (*fmt != '%') // usual char
		255	{
		256	ch = vgetc(&save, src);
		257	if (ch != *fmt++) // char not match format
		258	{
		259	vungetc(&save, ch, src);
		260	break;
		261	}
		262	pos++;
		263	continue;
		264	}
		265
		266	if (*(fmt + 1) == '%') // %%
		267	{
		268	ch = vgetc(&save, src);
		269	if (ch != '%') // char not match format
		270	{
		271	vungetc(&save, ch, src);
		272	break;
		273	}
		274	pos++;
		275	fmt += 2;
		276	continue;
		277	}
		278	//checking to containg format in the string
		279	fmtc = fmt;
		280	posc = pos;
		281
		282	flags = 0;
		283	format_flag = 0;
		284	flag_long = 0; // 2 = long double or long long int or wchar
		285
		286	while(*fmtc != '\0' && !format_flag) // searching end of format
		287	{
		288	fmtc++; posc++;
		289	switch( *fmtc )
		290	{
		291	case 'a':
		292	format_flag = 1;
		293	flags \|= flag_unsigned;
		294	break;
		295	case 'c': case 'd': case 'i': case 'e': case 'f': case 'g': case 's': case 'n':
		296	format_flag = 1;
		297	break;
		298	case 'l':
		299	flag_long = flag_long ? 2 : 1; // ll.eq.L
		300	break;
		301	case 'L':
		302	flag_long = 2;
		303	break;
		304	case 'o': case 'u': case 'x': case 'p':
		305	format_flag = 1;
		306	flags \|= flag_unsigned;
		307	break;
		308	case '*': case '.': // just skip
		309	break;
		310	default:
		311	if(isdigit(*fmtc)) break;
		312	goto exit_me; // non format char found - user error
		313	}
		314	}
		315
		316	if (format_flag == 0)
		317	{
		318	goto exit_me; // format char not found - user error
		319	}
		320
		321	fmt1 = 0;
		322	fmt2 = 0;
		323	if (posc - pos > 1) // try to read width, precision
		324	{
		325	fmt++;
		326	for(i = pos + 1; i < posc; i++)
		327	{
		328	switch(*fmt)
		329	{
		330	case '0':
		331	if(fmt1 == 0 && (flags & flag_point) == 0) flags \|= flag_lead_zeros;
		332	case '1': case '2': case '3': case '4':
		333	case '5': case '6': case '7': case '8': case '9':
		334	if ((flags & flag_point) == 0)
		335	fmt1 = fmt1 * 10 + (*fmt -'0');
		336	else
		337	fmt2 = fmt2 * 10 + (*fmt -'0');
		338	break;
		339	case '*':
		340	if (flag_point == 0)
		341	fmt1 = va_arg(argp, int);
		342	else
		343	fmt2 = va_arg(argp, int);
		344	break;
		345	case '.':
		346	flags \|= flag_point;
		347	break;
		348	case 'l': case 'L': // valid chars - skip
		349	break;
		350	default: // must be error
		351	goto exit_me; // format char not found - user error
		352	}
		353	fmt++;
		354	}
		355	}
		356
		357	// do real work - format arguments values
		358	// skip input spaces
		359	do {
		360	ch = vgetc(&save, src);
		361	if (ch == EOF) goto exit_me;
		362	} while (isspace(ch));
		363
		364	switch(*fmtc)
		365	{
		366	case 'n':
		367	point_to_n = va_arg(argp, int*);
		368	vungetc(&save, ch, src);
		369	break;
		370	case 'c': // read width chars, ever spaces
		371	arg_str = va_arg(argp, char*);
		372	if (fmt1 == 0) length = 1;
		373	else length = fmt1;
6432	siemargl	374	for (i = 0; i < length;)
6431	siemargl	375	{
6432	siemargl	376	*arg_str++ = ch; i++;
6431	siemargl	377	ch = vgetc(&save, src);
		378	if (ch == EOF) break;
		379	}
		380	if (i < length) goto exit_me; // not enough chars
		381	break;
		382	case 's':
		383	arg_str = va_arg(argp, char*);
		384	if (fmt1 == 0) length = 4095; // max string scan 4096
		385	else length = fmt1;
		386	for (i = 0; i < length; i++)
		387	{
		388	*arg_str++ = ch;
		389	ch = vgetc(&save, src);
		390	if (ch == EOF \|\| isspace(ch)) break; // ok, just finish string
		391	}
		392	*arg_str++ = '\0';
		393	break;
		394	case 'd': case 'i': case 'u':
		395	case 'o': case 'p': case 'x':
		396	i = try_parse_int(&digit, ch, src, &save, vgetc, vungetc);
		397	if (i < 0) goto exit_me;
		398
		399	if (flag_long == 0) { arg_int = va_arg(argp, int); arg_int = (int)digit; } else
		400	if (flag_long == 1) { arg_long = va_arg(argp, long); arg_long = (long)digit; } else
		401	if (flag_long == 2) { arg_longlong = va_arg(argp, long long); arg_longlong = digit; }
		402	break;
		403	case 'a': case 'A': case 'f': case 'F':
		404	case 'e': case 'E':
		405	case 'g': case 'G':
		406	i = try_parse_real(&real, ch, src, &save, vgetc, vungetc);
		407	if (i < 0) goto exit_me;
		408
		409	if (flag_long == 0) { arg_float = va_arg(argp, float); arg_float = (float)real; } else
		410	if (flag_long == 1) { arg_double = va_arg(argp, double); arg_double = (double)real; } else
		411	if (flag_long == 2) { arg_longdouble = va_arg(argp, long double); arg_longdouble = real; }
		412	break;
		413	}
		414
		415	fmt = fmtc + 1;
		416	nread++;
		417	}
		418	exit_me:
		419	if (point_to_n) *point_to_n = nread;
		420	return nread;
		421	}

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(root)/programs/develop/ktcc/trunk/libc/stdio/format_scan.c – Rev 6432