1 /****************************************************************************
2  * Copyright (c) 1998-2003,2004 Free Software Foundation, Inc.              *
3  *                                                                          *
4  * Permission is hereby granted, free of charge, to any person obtaining a  *
5  * copy of this software and associated documentation files (the            *
6  * "Software"), to deal in the Software without restriction, including      *
7  * without limitation the rights to use, copy, modify, merge, publish,      *
8  * distribute, distribute with modifications, sublicense, and/or sell       *
9  * copies of the Software, and to permit persons to whom the Software is    *
10  * furnished to do so, subject to the following conditions:                 *
11  *                                                                          *
12  * The above copyright notice and this permission notice shall be included  *
13  * in all copies or substantial portions of the Software.                   *
14  *                                                                          *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
24  * holders shall not be used in advertising or otherwise to promote the     *
25  * sale, use or other dealings in this Software without prior written       *
26  * authorization.                                                           *
27  ****************************************************************************/
28 
29 /****************************************************************************
30  *  State-machine fallback written by Thomas E. Dickey 2002                 *
31  ****************************************************************************/
32 
33 /*
34  * This function is needed to support vwscanw
35  */
36 
37 #include <curses.priv.h>
38 
39 #if !HAVE_VSSCANF
40 
41 MODULE_ID("$Id: vsscanf.c,v 1.18 2004/04/03 20:27:02 tom Exp $")
42 
43 #if !(HAVE_VFSCANF || HAVE__DOSCAN)
44 
45 #include <ctype.h>
46 
47 #define L_SQUARE '['
48 #define R_SQUARE ']'
49 
50 typedef enum {
51     cUnknown
52     ,cError			/* anything that isn't ANSI */
53     ,cAssigned
54     ,cChar
55     ,cInt
56     ,cFloat
57     ,cDouble
58     ,cPointer
59     ,cLong
60     ,cShort
61     ,cRange
62     ,cString
63 } ChunkType;
64 
65 typedef enum {
66     oUnknown
67     ,oShort
68     ,oLong
69 } OtherType;
70 
71 typedef enum {
72     sUnknown
73     ,sPercent			/* last was '%' beginning a format */
74     ,sNormal			/* ...somewhere in the middle */
75     ,sLeft			/* last was left square bracket beginning a range */
76     ,sRange			/* ...somewhere in the middle */
77     ,sFinal			/* last finished a format */
78 } ScanState;
79 
80 static ChunkType
81 final_ch(int ch, OtherType other)
82 {
83     ChunkType result = cUnknown;
84 
85     switch (ch) {
86     case 'c':
87 	if (other == oUnknown)
88 	    result = cChar;
89 	else
90 	    result = cError;
91 	break;
92     case 'd':
93     case 'i':
94     case 'X':
95     case 'x':
96 	switch (other) {
97 	case oUnknown:
98 	    result = cInt;
99 	    break;
100 	case oShort:
101 	    result = cShort;
102 	    break;
103 	case oLong:
104 	    result = cLong;
105 	    break;
106 	}
107 	break;
108     case 'E':
109     case 'e':
110     case 'f':
111     case 'g':
112 	switch (other) {
113 	case oUnknown:
114 	    result = cFloat;
115 	    break;
116 	case oShort:
117 	    result = cError;
118 	    break;
119 	case oLong:
120 	    result = cDouble;
121 	    break;
122 	}
123 	break;
124     case 'n':
125 	if (other == oUnknown)
126 	    result = cAssigned;
127 	else
128 	    result = cError;
129 	break;
130     case 'p':
131 	if (other == oUnknown)
132 	    result = cPointer;
133 	else
134 	    result = cError;
135 	break;
136     case 's':
137 	if (other == oUnknown)
138 	    result = cString;
139 	else
140 	    result = cError;
141 	break;
142     }
143     return result;
144 }
145 
146 static OtherType
147 other_ch(int ch)
148 {
149     OtherType result = oUnknown;
150     switch (ch) {
151     case 'h':
152 	result = oShort;
153 	break;
154     case 'l':
155 	result = oLong;
156 	break;
157     }
158     return result;
159 }
160 #endif
161 
162 /*VARARGS2*/
163 NCURSES_EXPORT(int)
164 vsscanf(const char *str, const char *format, va_list ap)
165 {
166 #if HAVE_VFSCANF || HAVE__DOSCAN
167     /*
168      * This code should work on anything descended from AT&T SVr1.
169      */
170     FILE strbuf;
171 
172     strbuf._flag = _IOREAD;
173     strbuf._ptr = strbuf._base = (unsigned char *) str;
174     strbuf._cnt = strlen(str);
175     strbuf._file = _NFILE;
176 
177 #if HAVE_VFSCANF
178     return (vfscanf(&strbuf, format, ap));
179 #else
180     return (_doscan(&strbuf, format, ap));
181 #endif
182 #else
183     static int can_convert = -1;
184 
185     int assigned = 0;
186     int consumed = 0;
187 
188     T((T_CALLED("vsscanf(%s,%s,...)"),
189        _nc_visbuf2(1, str),
190        _nc_visbuf2(2, format)));
191 
192     /*
193      * This relies on having a working "%n" format conversion.  Check if it
194      * works.  Only very old C libraries do not support it.
195      *
196      * FIXME: move this check into the configure script.
197      */
198     if (can_convert < 0) {
199 	int check1;
200 	int check2;
201 	if (sscanf("123", "%d%n", &check1, &check2) > 0
202 	    && check1 == 123
203 	    && check2 == 3) {
204 	    can_convert = 1;
205 	} else {
206 	    can_convert = 0;
207 	}
208     }
209 
210     if (can_convert) {
211 	size_t len_fmt = strlen(format) + 32;
212 	char *my_fmt = malloc(len_fmt);
213 	ChunkType chunk, ctest;
214 	OtherType other, otest;
215 	ScanState state;
216 	unsigned n;
217 	int eaten;
218 	void *pointer;
219 
220 	if (my_fmt != 0) {
221 	    /*
222 	     * Split the original format into chunks, adding a "%n" to the end
223 	     * of each (except of course if it used %n), and use that
224 	     * information to decide where to start scanning the next chunk.
225 	     *
226 	     * FIXME:  does %n count bytes or characters?  If the latter, this
227 	     * will require further work for multibyte strings.
228 	     */
229 	    while (*format != '\0') {
230 		/* find a chunk */
231 		state = sUnknown;
232 		chunk = cUnknown;
233 		other = oUnknown;
234 		pointer = 0;
235 		for (n = 0; format[n] != 0 && state != sFinal; ++n) {
236 		    my_fmt[n] = format[n];
237 		    switch (state) {
238 		    case sUnknown:
239 			if (format[n] == '%')
240 			    state = sPercent;
241 			break;
242 		    case sPercent:
243 			if (format[n] == '%') {
244 			    state = sUnknown;
245 			} else if (format[n] == L_SQUARE) {
246 			    state = sLeft;
247 			} else {
248 			    state = sNormal;
249 			    --n;
250 			}
251 			break;
252 		    case sLeft:
253 			state = sRange;
254 			if (format[n] == '^') {
255 			    ++n;
256 			    my_fmt[n] = format[n];
257 			}
258 			break;
259 		    case sRange:
260 			if (format[n] == R_SQUARE) {
261 			    state = sFinal;
262 			    chunk = cRange;
263 			}
264 			break;
265 		    case sNormal:
266 			if (format[n] == '*') {
267 			    state = sUnknown;
268 			} else {
269 			    if ((ctest = final_ch(format[n], other)) != cUnknown) {
270 				state = sFinal;
271 				chunk = ctest;
272 			    } else if ((otest = other_ch(format[n])) != oUnknown) {
273 				other = otest;
274 			    } else if (isalpha(UChar(format[n]))) {
275 				state = sFinal;
276 				chunk = cError;
277 			    }
278 			}
279 			break;
280 		    case sFinal:
281 			break;
282 		    }
283 		}
284 		my_fmt[n] = '\0';
285 		format += n;
286 
287 		if (chunk == cUnknown
288 		    || chunk == cError) {
289 		    if (assigned == 0)
290 			assigned = EOF;
291 		    break;
292 		}
293 
294 		/* add %n, if the format was not that */
295 		if (chunk != cAssigned) {
296 		    strcat(my_fmt, "%n");
297 		}
298 
299 		switch (chunk) {
300 		case cAssigned:
301 		    strcat(my_fmt, "%n");
302 		    pointer = &eaten;
303 		    break;
304 		case cInt:
305 		    pointer = va_arg(ap, int *);
306 		    break;
307 		case cShort:
308 		    pointer = va_arg(ap, short *);
309 		    break;
310 		case cFloat:
311 		    pointer = va_arg(ap, float *);
312 		    break;
313 		case cDouble:
314 		    pointer = va_arg(ap, double *);
315 		    break;
316 		case cLong:
317 		    pointer = va_arg(ap, long *);
318 		    break;
319 		case cPointer:
320 		    pointer = va_arg(ap, void *);
321 		    break;
322 		case cChar:
323 		case cRange:
324 		case cString:
325 		    pointer = va_arg(ap, char *);
326 		    break;
327 		case cError:
328 		case cUnknown:
329 		    break;
330 		}
331 		/* do the conversion */
332 		T(("...converting chunk #%d type %d(%s,%s)",
333 		   assigned + 1, chunk,
334 		   _nc_visbuf2(1, str + consumed),
335 		   _nc_visbuf2(2, my_fmt)));
336 		if (sscanf(str + consumed, my_fmt, pointer, &eaten) > 0)
337 		    consumed += eaten;
338 		else
339 		    break;
340 		++assigned;
341 	    }
342 	    free(my_fmt);
343 	}
344     }
345     returnCode(assigned);
346 #endif
347 }
348 #else
349 extern
350 NCURSES_EXPORT(void)
351 _nc_vsscanf(void);		/* quiet's gcc warning */
352 NCURSES_EXPORT(void)
353 _nc_vsscanf(void)
354 {
355 }				/* nonempty for strict ANSI compilers */
356 #endif /* !HAVE_VSSCANF */
357