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3686044d KB |
1 | /*- |
2 | * Copyright (c) 1990 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * Chris Torek. | |
7 | * | |
8 | * %sccs.include.redist.c% | |
9 | */ | |
10 | ||
2ce81398 | 11 | #if defined(LIBC_SCCS) && !defined(lint) |
cb631443 | 12 | static char sccsid[] = "@(#)vfscanf.c 5.6 (Berkeley) %G%"; |
3686044d | 13 | #endif /* LIBC_SCCS and not lint */ |
87bdee5f | 14 | |
87bdee5f | 15 | #include <stdio.h> |
3686044d | 16 | #include <stdlib.h> |
cb631443 | 17 | #include <ctype.h> |
3686044d KB |
18 | #if __STDC__ |
19 | #include <stdarg.h> | |
20 | #else | |
21 | #include <varargs.h> | |
22 | #endif | |
23 | #include "local.h" | |
24 | ||
25 | #define FLOATING_POINT | |
26 | ||
27 | #ifdef FLOATING_POINT | |
28 | #include "floatio.h" | |
29 | #define BUF (MAXEXP+MAXFRACT+3) /* 3 = sign + decimal point + NUL */ | |
30 | #else | |
31 | #define BUF 40 | |
32 | #endif | |
33 | ||
34 | /* | |
35 | * Flags used during conversion. | |
36 | */ | |
37 | #define LONG 0x01 /* l: long or double */ | |
38 | #define LONGDBL 0x02 /* L: long double; unimplemented */ | |
39 | #define SHORT 0x04 /* h: short */ | |
40 | #define SUPPRESS 0x08 /* suppress assignment */ | |
41 | #define POINTER 0x10 /* weird %p pointer (`fake hex') */ | |
42 | #define NOSKIP 0x20 /* do not skip blanks */ | |
43 | ||
44 | /* | |
45 | * The following are used in numeric conversions only: | |
46 | * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; | |
47 | * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. | |
48 | */ | |
49 | #define SIGNOK 0x40 /* +/- is (still) legal */ | |
50 | #define NDIGITS 0x80 /* no digits detected */ | |
51 | ||
52 | #define DPTOK 0x100 /* (float) decimal point is still legal */ | |
53 | #define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */ | |
54 | ||
55 | #define PFXOK 0x100 /* 0x prefix is (still) legal */ | |
56 | #define NZDIGITS 0x200 /* no zero digits detected */ | |
57 | ||
58 | /* | |
59 | * Conversion types. | |
60 | */ | |
61 | #define CT_CHAR 0 /* %c conversion */ | |
62 | #define CT_CCL 1 /* %[...] conversion */ | |
63 | #define CT_STRING 2 /* %s conversion */ | |
64 | #define CT_INT 3 /* integer, i.e., strtol or strtoul */ | |
65 | #define CT_FLOAT 4 /* floating, i.e., strtod */ | |
66 | ||
67 | #define u_char unsigned char | |
68 | #define u_long unsigned long | |
69 | ||
70 | static u_char *__sccl(); | |
71 | ||
72 | /* | |
73 | * vfscanf | |
74 | */ | |
75 | __svfscanf(fp, fmt0, ap) | |
76 | register FILE *fp; | |
77 | char const *fmt0; | |
78 | va_list ap; | |
87bdee5f | 79 | { |
3686044d KB |
80 | register u_char *fmt = (u_char *)fmt0; |
81 | register int c; /* character from format, or conversion */ | |
82 | register size_t width; /* field width, or 0 */ | |
83 | register char *p; /* points into all kinds of strings */ | |
84 | register int n; /* handy integer */ | |
85 | register int flags; /* flags as defined above */ | |
86 | register char *p0; /* saves original value of p when necessary */ | |
87 | int nassigned; /* number of fields assigned */ | |
88 | int nread; /* number of characters consumed from fp */ | |
89 | int base; /* base argument to strtol/strtoul */ | |
90 | u_long (*ccfn)(); /* conversion function (strtol/strtoul) */ | |
91 | char ccltab[256]; /* character class table for %[...] */ | |
92 | char buf[BUF]; /* buffer for numeric conversions */ | |
93 | ||
94 | /* `basefix' is used to avoid `if' tests in the integer scanner */ | |
95 | static short basefix[17] = | |
96 | { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; | |
97 | ||
98 | nassigned = 0; | |
99 | nread = 0; | |
c10ce770 CT |
100 | base = 0; /* XXX just to keep gcc happy */ |
101 | ccfn = NULL; /* XXX just to keep gcc happy */ | |
3686044d KB |
102 | for (;;) { |
103 | c = *fmt++; | |
104 | if (c == 0) | |
105 | return (nassigned); | |
106 | if (isspace(c)) { | |
107 | for (;;) { | |
108 | if (fp->_r <= 0 && __srefill(fp)) | |
109 | return (nassigned); | |
110 | if (!isspace(*fp->_p)) | |
111 | break; | |
112 | nread++, fp->_r--, fp->_p++; | |
113 | } | |
114 | continue; | |
87bdee5f | 115 | } |
3686044d KB |
116 | if (c != '%') |
117 | goto literal; | |
118 | width = 0; | |
119 | flags = 0; | |
120 | /* | |
121 | * switch on the format. continue if done; | |
122 | * break once format type is derived. | |
123 | */ | |
124 | again: c = *fmt++; | |
125 | switch (c) { | |
126 | case '%': | |
127 | literal: | |
128 | if (fp->_r <= 0 && __srefill(fp)) | |
129 | goto input_failure; | |
130 | if (*fp->_p != c) | |
131 | goto match_failure; | |
132 | fp->_r--, fp->_p++; | |
133 | nread++; | |
134 | continue; | |
87bdee5f | 135 | |
3686044d KB |
136 | case '*': |
137 | flags |= SUPPRESS; | |
138 | goto again; | |
139 | case 'l': | |
140 | flags |= LONG; | |
141 | goto again; | |
142 | case 'L': | |
143 | flags |= LONGDBL; | |
144 | goto again; | |
145 | case 'h': | |
146 | flags |= SHORT; | |
147 | goto again; | |
148 | ||
149 | case '0': case '1': case '2': case '3': case '4': | |
150 | case '5': case '6': case '7': case '8': case '9': | |
151 | width = width * 10 + c - '0'; | |
152 | goto again; | |
153 | ||
154 | /* | |
155 | * Conversions. | |
156 | * Those marked `compat' are for 4.[123]BSD compatibility. | |
157 | * | |
158 | * (According to ANSI, E and X formats are supposed | |
159 | * to the same as e and x. Sorry about that.) | |
160 | */ | |
161 | case 'D': /* compat */ | |
162 | flags |= LONG; | |
163 | /* FALLTHROUGH */ | |
164 | case 'd': | |
165 | c = CT_INT; | |
166 | ccfn = (u_long (*)())strtol; | |
167 | base = 10; | |
168 | break; | |
169 | ||
170 | case 'i': | |
171 | c = CT_INT; | |
172 | ccfn = (u_long (*)())strtol; | |
173 | base = 0; | |
174 | break; | |
175 | ||
176 | case 'O': /* compat */ | |
177 | flags |= LONG; | |
178 | /* FALLTHROUGH */ | |
179 | case 'o': | |
180 | c = CT_INT; | |
181 | ccfn = strtoul; | |
182 | base = 8; | |
183 | break; | |
184 | ||
185 | case 'u': | |
186 | c = CT_INT; | |
187 | ccfn = strtoul; | |
188 | base = 10; | |
189 | break; | |
190 | ||
191 | case 'X': /* compat XXX */ | |
192 | flags |= LONG; | |
193 | /* FALLTHROUGH */ | |
194 | case 'x': | |
195 | flags |= PFXOK; /* enable 0x prefixing */ | |
196 | c = CT_INT; | |
197 | ccfn = strtoul; | |
198 | base = 16; | |
199 | break; | |
200 | ||
201 | #ifdef FLOATING_POINT | |
202 | case 'E': /* compat XXX */ | |
203 | case 'F': /* compat */ | |
204 | flags |= LONG; | |
205 | /* FALLTHROUGH */ | |
206 | case 'e': case 'f': case 'g': | |
207 | c = CT_FLOAT; | |
208 | break; | |
209 | #endif | |
210 | ||
211 | case 's': | |
212 | c = CT_STRING; | |
213 | break; | |
214 | ||
215 | case '[': | |
216 | fmt = __sccl(ccltab, fmt); | |
217 | flags |= NOSKIP; | |
218 | c = CT_CCL; | |
219 | break; | |
220 | ||
221 | case 'c': | |
222 | flags |= NOSKIP; | |
223 | c = CT_CHAR; | |
224 | break; | |
225 | ||
226 | case 'p': /* pointer format is like hex */ | |
227 | flags |= POINTER | PFXOK; | |
228 | c = CT_INT; | |
229 | ccfn = strtoul; | |
230 | base = 16; | |
231 | break; | |
232 | ||
233 | case 'n': | |
234 | if (flags & SUPPRESS) /* ??? */ | |
235 | continue; | |
236 | if (flags & SHORT) | |
237 | *va_arg(ap, short *) = nread; | |
238 | else if (flags & LONG) | |
239 | *va_arg(ap, long *) = nread; | |
87bdee5f | 240 | else |
3686044d | 241 | *va_arg(ap, int *) = nread; |
87bdee5f | 242 | continue; |
3686044d KB |
243 | |
244 | /* | |
245 | * Disgusting backwards compatibility hacks. XXX | |
246 | */ | |
247 | case '\0': /* compat */ | |
248 | return (EOF); | |
249 | ||
250 | default: /* compat */ | |
251 | if (isupper(c)) | |
252 | flags |= LONG; | |
253 | c = CT_INT; | |
254 | ccfn = (u_long (*)())strtol; | |
255 | base = 10; | |
256 | break; | |
257 | } | |
258 | ||
259 | /* | |
260 | * We have a conversion that requires input. | |
261 | */ | |
262 | if (fp->_r <= 0 && __srefill(fp)) | |
263 | goto input_failure; | |
264 | ||
265 | /* | |
266 | * Consume leading white space, except for formats | |
267 | * that suppress this. | |
268 | */ | |
269 | if ((flags & NOSKIP) == 0) { | |
270 | while (isspace(*fp->_p)) { | |
271 | nread++; | |
272 | if (--fp->_r > 0) | |
273 | fp->_p++; | |
274 | else if (__srefill(fp)) | |
275 | goto input_failure; | |
276 | } | |
277 | /* | |
278 | * Note that there is at least one character in | |
279 | * the buffer, so conversions that do not set NOSKIP | |
280 | * ca no longer result in an input failure. | |
281 | */ | |
282 | } | |
283 | ||
284 | /* | |
285 | * Do the conversion. | |
286 | */ | |
287 | switch (c) { | |
288 | ||
289 | case CT_CHAR: | |
290 | /* scan arbitrary characters (sets NOSKIP) */ | |
291 | if (width == 0) | |
292 | width = 1; | |
293 | if (flags & SUPPRESS) { | |
294 | size_t sum = 0; | |
295 | for (;;) { | |
296 | if ((n = fp->_r) < width) { | |
297 | sum += n; | |
298 | width -= n; | |
299 | fp->_p += n; | |
300 | if (__srefill(fp)) { | |
301 | if (sum == 0) | |
302 | goto input_failure; | |
303 | break; | |
304 | } | |
305 | } else { | |
306 | sum += width; | |
307 | fp->_r -= width; | |
308 | fp->_p += width; | |
309 | break; | |
310 | } | |
311 | } | |
312 | nread += sum; | |
313 | } else { | |
314 | size_t r = fread((void *)va_arg(ap, char *), 1, | |
315 | width, fp); | |
316 | ||
317 | if (r == 0) | |
318 | goto input_failure; | |
319 | nread += r; | |
320 | nassigned++; | |
321 | } | |
322 | break; | |
323 | ||
324 | case CT_CCL: | |
325 | /* scan a (nonempty) character class (sets NOSKIP) */ | |
326 | if (width == 0) | |
327 | width = ~0; /* `infinity' */ | |
328 | /* take only those things in the class */ | |
329 | if (flags & SUPPRESS) { | |
330 | n = 0; | |
331 | while (ccltab[*fp->_p]) { | |
332 | n++, fp->_r--, fp->_p++; | |
333 | if (--width == 0) | |
334 | break; | |
335 | if (fp->_r <= 0 && __srefill(fp)) { | |
336 | if (n == 0) | |
337 | goto input_failure; | |
338 | break; | |
339 | } | |
340 | } | |
341 | if (n == 0) | |
342 | goto match_failure; | |
343 | } else { | |
344 | p0 = p = va_arg(ap, char *); | |
345 | while (ccltab[*fp->_p]) { | |
346 | fp->_r--; | |
347 | *p++ = *fp->_p++; | |
348 | if (--width == 0) | |
349 | break; | |
350 | if (fp->_r <= 0 && __srefill(fp)) { | |
351 | if (p == p0) | |
352 | goto input_failure; | |
353 | break; | |
354 | } | |
355 | } | |
356 | n = p - p0; | |
357 | if (n == 0) | |
358 | goto match_failure; | |
359 | *p = 0; | |
360 | nassigned++; | |
361 | } | |
362 | nread += n; | |
363 | break; | |
364 | ||
365 | case CT_STRING: | |
366 | /* like CCL, but zero-length string OK, & no NOSKIP */ | |
367 | if (width == 0) | |
368 | width = ~0; | |
369 | if (flags & SUPPRESS) { | |
370 | n = 0; | |
371 | while (!isspace(*fp->_p)) { | |
372 | n++, fp->_r--, fp->_p++; | |
373 | if (--width == 0) | |
374 | break; | |
375 | if (fp->_r <= 0 && __srefill(fp)) | |
376 | break; | |
377 | } | |
378 | nread += n; | |
379 | } else { | |
380 | p0 = p = va_arg(ap, char *); | |
381 | while (!isspace(*fp->_p)) { | |
382 | fp->_r--; | |
383 | *p++ = *fp->_p++; | |
384 | if (--width == 0) | |
385 | break; | |
386 | if (fp->_r <= 0 && __srefill(fp)) | |
387 | break; | |
388 | } | |
389 | *p = 0; | |
390 | nread += p - p0; | |
391 | nassigned++; | |
392 | } | |
87bdee5f | 393 | continue; |
3686044d KB |
394 | |
395 | case CT_INT: | |
396 | /* scan an integer as if by strtol/strtoul */ | |
397 | #ifdef hardway | |
398 | if (width == 0 || width > sizeof(buf) - 1) | |
399 | width = sizeof(buf) - 1; | |
400 | #else | |
401 | /* size_t is unsigned, hence this optimisation */ | |
402 | if (--width > sizeof(buf) - 2) | |
403 | width = sizeof(buf) - 2; | |
404 | width++; | |
405 | #endif | |
406 | flags |= SIGNOK | NDIGITS | NZDIGITS; | |
407 | for (p = buf; width; width--) { | |
408 | c = *fp->_p; | |
409 | /* | |
410 | * Switch on the character; `goto ok' | |
411 | * if we accept it as a part of number. | |
412 | */ | |
413 | switch (c) { | |
414 | ||
415 | /* | |
416 | * The digit 0 is always legal, but is | |
417 | * special. For %i conversions, if no | |
418 | * digits (zero or nonzero) have been | |
419 | * scanned (only signs), we will have | |
420 | * base==0. In that case, we should set | |
421 | * it to 8 and enable 0x prefixing. | |
422 | * Also, if we have not scanned zero digits | |
423 | * before this, do not turn off prefixing | |
424 | * (someone else will turn it off if we | |
425 | * have scanned any nonzero digits). | |
426 | */ | |
427 | case '0': | |
428 | if (base == 0) { | |
429 | base = 8; | |
430 | flags |= PFXOK; | |
431 | } | |
432 | if (flags & NZDIGITS) | |
433 | flags &= ~(SIGNOK|NZDIGITS|NDIGITS); | |
434 | else | |
435 | flags &= ~(SIGNOK|PFXOK|NDIGITS); | |
436 | goto ok; | |
437 | ||
438 | /* 1 through 7 always legal */ | |
439 | case '1': case '2': case '3': | |
440 | case '4': case '5': case '6': case '7': | |
441 | base = basefix[base]; | |
442 | flags &= ~(SIGNOK | PFXOK | NDIGITS); | |
443 | goto ok; | |
444 | ||
445 | /* digits 8 and 9 ok iff decimal or hex */ | |
446 | case '8': case '9': | |
447 | base = basefix[base]; | |
448 | if (base <= 8) | |
449 | break; /* not legal here */ | |
450 | flags &= ~(SIGNOK | PFXOK | NDIGITS); | |
451 | goto ok; | |
452 | ||
453 | /* letters ok iff hex */ | |
454 | case 'A': case 'B': case 'C': | |
455 | case 'D': case 'E': case 'F': | |
456 | case 'a': case 'b': case 'c': | |
457 | case 'd': case 'e': case 'f': | |
458 | /* no need to fix base here */ | |
459 | if (base <= 10) | |
460 | break; /* not legal here */ | |
461 | flags &= ~(SIGNOK | PFXOK | NDIGITS); | |
462 | goto ok; | |
463 | ||
464 | /* sign ok only as first character */ | |
465 | case '+': case '-': | |
466 | if (flags & SIGNOK) { | |
467 | flags &= ~SIGNOK; | |
468 | goto ok; | |
469 | } | |
470 | break; | |
471 | ||
472 | /* x ok iff flag still set & 2nd char */ | |
473 | case 'x': case 'X': | |
474 | if (flags & PFXOK && p == buf + 1) { | |
475 | base = 16; /* if %i */ | |
476 | flags &= ~PFXOK; | |
477 | goto ok; | |
478 | } | |
479 | break; | |
480 | } | |
481 | ||
482 | /* | |
483 | * If we got here, c is not a legal character | |
484 | * for a number. Stop accumulating digits. | |
485 | */ | |
87bdee5f | 486 | break; |
3686044d KB |
487 | ok: |
488 | /* | |
489 | * c is legal: store it and look at the next. | |
490 | */ | |
491 | *p++ = c; | |
492 | if (--fp->_r > 0) | |
493 | fp->_p++; | |
494 | else if (__srefill(fp)) | |
495 | break; /* EOF */ | |
496 | } | |
497 | /* | |
498 | * If we had only a sign, it is no good; push | |
499 | * back the sign. If the number ends in `x', | |
500 | * it was [sign] '0' 'x', so push back the x | |
501 | * and treat it as [sign] '0'. | |
502 | */ | |
503 | if (flags & NDIGITS) { | |
504 | if (p > buf) | |
505 | (void) ungetc(*(u_char *)--p, fp); | |
506 | goto match_failure; | |
507 | } | |
508 | c = ((u_char *)p)[-1]; | |
509 | if (c == 'x' || c == 'X') { | |
510 | --p; | |
511 | (void) ungetc(c, fp); | |
512 | } | |
513 | if ((flags & SUPPRESS) == 0) { | |
514 | u_long res; | |
515 | ||
516 | *p = 0; | |
517 | res = (*ccfn)(buf, (char **)NULL, base); | |
518 | if (flags & POINTER) | |
519 | *va_arg(ap, void **) = (void *)res; | |
520 | else if (flags & SHORT) | |
521 | *va_arg(ap, short *) = res; | |
522 | else if (flags & LONG) | |
523 | *va_arg(ap, long *) = res; | |
524 | else | |
525 | *va_arg(ap, int *) = res; | |
526 | nassigned++; | |
527 | } | |
528 | nread += p - buf; | |
529 | break; | |
530 | ||
531 | #ifdef FLOATING_POINT | |
532 | case CT_FLOAT: | |
533 | /* scan a floating point number as if by strtod */ | |
534 | #ifdef hardway | |
535 | if (width == 0 || width > sizeof(buf) - 1) | |
536 | width = sizeof(buf) - 1; | |
537 | #else | |
538 | /* size_t is unsigned, hence this optimisation */ | |
539 | if (--width > sizeof(buf) - 2) | |
540 | width = sizeof(buf) - 2; | |
541 | width++; | |
542 | #endif | |
543 | flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; | |
544 | for (p = buf; width; width--) { | |
545 | c = *fp->_p; | |
546 | /* | |
547 | * This code mimicks the integer conversion | |
548 | * code, but is much simpler. | |
549 | */ | |
550 | switch (c) { | |
551 | ||
552 | case '0': case '1': case '2': case '3': | |
553 | case '4': case '5': case '6': case '7': | |
554 | case '8': case '9': | |
555 | flags &= ~(SIGNOK | NDIGITS); | |
556 | goto fok; | |
557 | ||
558 | case '+': case '-': | |
559 | if (flags & SIGNOK) { | |
560 | flags &= ~SIGNOK; | |
561 | goto fok; | |
562 | } | |
563 | break; | |
564 | case '.': | |
565 | if (flags & DPTOK) { | |
566 | flags &= ~(SIGNOK | DPTOK); | |
567 | goto fok; | |
568 | } | |
569 | break; | |
570 | case 'e': case 'E': | |
571 | /* no exponent without some digits */ | |
572 | if ((flags&(NDIGITS|EXPOK)) == EXPOK) { | |
573 | flags = | |
574 | (flags & ~(EXPOK|DPTOK)) | | |
575 | SIGNOK | NDIGITS; | |
576 | goto fok; | |
577 | } | |
578 | break; | |
579 | } | |
87bdee5f | 580 | break; |
3686044d KB |
581 | fok: |
582 | *p++ = c; | |
583 | if (--fp->_r > 0) | |
584 | fp->_p++; | |
585 | else if (__srefill(fp)) | |
586 | break; /* EOF */ | |
587 | } | |
588 | /* | |
589 | * If no digits, might be missing exponent digits | |
590 | * (just give back the exponent) or might be missing | |
591 | * regular digits, but had sign and/or decimal point. | |
592 | */ | |
593 | if (flags & NDIGITS) { | |
594 | if (flags & EXPOK) { | |
595 | /* no digits at all */ | |
596 | while (p > buf) | |
597 | ungetc(*(u_char *)--p, fp); | |
598 | goto match_failure; | |
599 | } | |
600 | /* just a bad exponent (e and maybe sign) */ | |
601 | c = *(u_char *)--p; | |
602 | if (c != 'e' && c != 'E') { | |
603 | (void) ungetc(c, fp);/* sign */ | |
604 | c = *(u_char *)--p; | |
605 | } | |
606 | (void) ungetc(c, fp); | |
607 | } | |
608 | if ((flags & SUPPRESS) == 0) { | |
609 | double res; | |
610 | ||
611 | *p = 0; | |
612 | res = atof(buf); | |
613 | if (flags & LONG) | |
614 | *va_arg(ap, double *) = res; | |
615 | else | |
616 | *va_arg(ap, float *) = res; | |
617 | nassigned++; | |
618 | } | |
619 | nread += p - buf; | |
87bdee5f | 620 | break; |
3686044d KB |
621 | #endif /* FLOATING_POINT */ |
622 | } | |
87bdee5f | 623 | } |
3686044d KB |
624 | input_failure: |
625 | return (nassigned ? nassigned : -1); | |
626 | match_failure: | |
627 | return (nassigned); | |
87bdee5f KM |
628 | } |
629 | ||
3686044d KB |
630 | /* |
631 | * Fill in the given table from the scanset at the given format | |
632 | * (just after `['). Return a pointer to the character past the | |
633 | * closing `]'. The table has a 1 wherever characters should be | |
634 | * considered part of the scanset. | |
635 | */ | |
636 | static u_char * | |
637 | __sccl(tab, fmt) | |
638 | register char *tab; | |
639 | register u_char *fmt; | |
87bdee5f | 640 | { |
3686044d KB |
641 | register int c, n, v; |
642 | ||
643 | /* first `clear' the whole table */ | |
644 | c = *fmt++; /* first char hat => negated scanset */ | |
645 | if (c == '^') { | |
646 | v = 1; /* default => accept */ | |
647 | c = *fmt++; /* get new first char */ | |
87bdee5f | 648 | } else |
3686044d KB |
649 | v = 0; /* default => reject */ |
650 | /* should probably use memset here */ | |
651 | for (n = 0; n < 256; n++) | |
652 | tab[n] = v; | |
653 | if (c == 0) | |
654 | return (fmt - 1);/* format ended before closing ] */ | |
87bdee5f | 655 | |
3686044d KB |
656 | /* |
657 | * Now set the entries corresponding to the actual scanset | |
658 | * to the opposite of the above. | |
659 | * | |
660 | * The first character may be ']' (or '-') without being special; | |
661 | * the last character may be '-'. | |
662 | */ | |
663 | v = 1 - v; | |
664 | for (;;) { | |
665 | tab[c] = v; /* take character c */ | |
666 | doswitch: | |
667 | n = *fmt++; /* and examine the next */ | |
668 | switch (n) { | |
87bdee5f | 669 | |
3686044d KB |
670 | case 0: /* format ended too soon */ |
671 | return (fmt - 1); | |
672 | ||
673 | case '-': | |
674 | /* | |
675 | * A scanset of the form | |
676 | * [01+-] | |
677 | * is defined as `the digit 0, the digit 1, | |
678 | * the character +, the character -', but | |
679 | * the effect of a scanset such as | |
680 | * [a-zA-Z0-9] | |
681 | * is implementation defined. The V7 Unix | |
682 | * scanf treats `a-z' as `the letters a through | |
683 | * z', but treats `a-a' as `the letter a, the | |
684 | * character -, and the letter a'. | |
685 | * | |
686 | * For compatibility, the `-' is not considerd | |
687 | * to define a range if the character following | |
688 | * it is either a close bracket (required by ANSI) | |
689 | * or is not numerically greater than the character | |
690 | * we just stored in the table (c). | |
691 | */ | |
692 | n = *fmt; | |
693 | if (n == ']' || n < c) { | |
694 | c = '-'; | |
695 | break; /* resume the for(;;) */ | |
696 | } | |
697 | fmt++; | |
698 | do { /* fill in the range */ | |
699 | tab[++c] = v; | |
700 | } while (c < n); | |
701 | #if 1 /* XXX another disgusting compatibility hack */ | |
702 | /* | |
703 | * Alas, the V7 Unix scanf also treats formats | |
704 | * such as [a-c-e] as `the letters a through e'. | |
705 | * This too is permitted by the standard.... | |
706 | */ | |
707 | goto doswitch; | |
708 | #else | |
709 | c = *fmt++; | |
710 | if (c == 0) | |
711 | return (fmt - 1); | |
712 | if (c == ']') | |
713 | return (fmt); | |
714 | #endif | |
715 | break; | |
716 | ||
717 | case ']': /* end of scanset */ | |
718 | return (fmt); | |
719 | ||
720 | default: /* just another character */ | |
721 | c = n; | |
722 | break; | |
723 | } | |
87bdee5f | 724 | } |
3686044d | 725 | /* NOTREACHED */ |
87bdee5f | 726 | } |