Commit | Line | Data |
---|---|---|
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) |
3686044d KB |
12 | static char sccsid[] = "@(#)vfscanf.c 5.3 (Berkeley) %G%"; |
13 | #endif /* LIBC_SCCS and not lint */ | |
87bdee5f | 14 | |
3686044d | 15 | #include <sys/stdc.h> |
87bdee5f | 16 | #include <stdio.h> |
3686044d KB |
17 | #include <ctype.h> |
18 | #include <stdlib.h> | |
19 | #if __STDC__ | |
20 | #include <stdarg.h> | |
21 | #else | |
22 | #include <varargs.h> | |
23 | #endif | |
24 | #include "local.h" | |
25 | ||
26 | #define FLOATING_POINT | |
27 | ||
28 | #ifdef FLOATING_POINT | |
29 | #include "floatio.h" | |
30 | #define BUF (MAXEXP+MAXFRACT+3) /* 3 = sign + decimal point + NUL */ | |
31 | #else | |
32 | #define BUF 40 | |
33 | #endif | |
34 | ||
35 | /* | |
36 | * Flags used during conversion. | |
37 | */ | |
38 | #define LONG 0x01 /* l: long or double */ | |
39 | #define LONGDBL 0x02 /* L: long double; unimplemented */ | |
40 | #define SHORT 0x04 /* h: short */ | |
41 | #define SUPPRESS 0x08 /* suppress assignment */ | |
42 | #define POINTER 0x10 /* weird %p pointer (`fake hex') */ | |
43 | #define NOSKIP 0x20 /* do not skip blanks */ | |
44 | ||
45 | /* | |
46 | * The following are used in numeric conversions only: | |
47 | * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; | |
48 | * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. | |
49 | */ | |
50 | #define SIGNOK 0x40 /* +/- is (still) legal */ | |
51 | #define NDIGITS 0x80 /* no digits detected */ | |
52 | ||
53 | #define DPTOK 0x100 /* (float) decimal point is still legal */ | |
54 | #define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */ | |
55 | ||
56 | #define PFXOK 0x100 /* 0x prefix is (still) legal */ | |
57 | #define NZDIGITS 0x200 /* no zero digits detected */ | |
58 | ||
59 | /* | |
60 | * Conversion types. | |
61 | */ | |
62 | #define CT_CHAR 0 /* %c conversion */ | |
63 | #define CT_CCL 1 /* %[...] conversion */ | |
64 | #define CT_STRING 2 /* %s conversion */ | |
65 | #define CT_INT 3 /* integer, i.e., strtol or strtoul */ | |
66 | #define CT_FLOAT 4 /* floating, i.e., strtod */ | |
67 | ||
68 | #define u_char unsigned char | |
69 | #define u_long unsigned long | |
70 | ||
71 | static u_char *__sccl(); | |
72 | ||
73 | /* | |
74 | * vfscanf | |
75 | */ | |
76 | __svfscanf(fp, fmt0, ap) | |
77 | register FILE *fp; | |
78 | char const *fmt0; | |
79 | va_list ap; | |
87bdee5f | 80 | { |
3686044d KB |
81 | register u_char *fmt = (u_char *)fmt0; |
82 | register int c; /* character from format, or conversion */ | |
83 | register size_t width; /* field width, or 0 */ | |
84 | register char *p; /* points into all kinds of strings */ | |
85 | register int n; /* handy integer */ | |
86 | register int flags; /* flags as defined above */ | |
87 | register char *p0; /* saves original value of p when necessary */ | |
88 | int nassigned; /* number of fields assigned */ | |
89 | int nread; /* number of characters consumed from fp */ | |
90 | int base; /* base argument to strtol/strtoul */ | |
91 | u_long (*ccfn)(); /* conversion function (strtol/strtoul) */ | |
92 | char ccltab[256]; /* character class table for %[...] */ | |
93 | char buf[BUF]; /* buffer for numeric conversions */ | |
94 | ||
95 | /* `basefix' is used to avoid `if' tests in the integer scanner */ | |
96 | static short basefix[17] = | |
97 | { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; | |
98 | ||
99 | nassigned = 0; | |
100 | nread = 0; | |
101 | for (;;) { | |
102 | c = *fmt++; | |
103 | if (c == 0) | |
104 | return (nassigned); | |
105 | if (isspace(c)) { | |
106 | for (;;) { | |
107 | if (fp->_r <= 0 && __srefill(fp)) | |
108 | return (nassigned); | |
109 | if (!isspace(*fp->_p)) | |
110 | break; | |
111 | nread++, fp->_r--, fp->_p++; | |
112 | } | |
113 | continue; | |
87bdee5f | 114 | } |
3686044d KB |
115 | if (c != '%') |
116 | goto literal; | |
117 | width = 0; | |
118 | flags = 0; | |
119 | /* | |
120 | * switch on the format. continue if done; | |
121 | * break once format type is derived. | |
122 | */ | |
123 | again: c = *fmt++; | |
124 | switch (c) { | |
125 | case '%': | |
126 | literal: | |
127 | if (fp->_r <= 0 && __srefill(fp)) | |
128 | goto input_failure; | |
129 | if (*fp->_p != c) | |
130 | goto match_failure; | |
131 | fp->_r--, fp->_p++; | |
132 | nread++; | |
133 | continue; | |
87bdee5f | 134 | |
3686044d KB |
135 | case '*': |
136 | flags |= SUPPRESS; | |
137 | goto again; | |
138 | case 'l': | |
139 | flags |= LONG; | |
140 | goto again; | |
141 | case 'L': | |
142 | flags |= LONGDBL; | |
143 | goto again; | |
144 | case 'h': | |
145 | flags |= SHORT; | |
146 | goto again; | |
147 | ||
148 | case '0': case '1': case '2': case '3': case '4': | |
149 | case '5': case '6': case '7': case '8': case '9': | |
150 | width = width * 10 + c - '0'; | |
151 | goto again; | |
152 | ||
153 | /* | |
154 | * Conversions. | |
155 | * Those marked `compat' are for 4.[123]BSD compatibility. | |
156 | * | |
157 | * (According to ANSI, E and X formats are supposed | |
158 | * to the same as e and x. Sorry about that.) | |
159 | */ | |
160 | case 'D': /* compat */ | |
161 | flags |= LONG; | |
162 | /* FALLTHROUGH */ | |
163 | case 'd': | |
164 | c = CT_INT; | |
165 | ccfn = (u_long (*)())strtol; | |
166 | base = 10; | |
167 | break; | |
168 | ||
169 | case 'i': | |
170 | c = CT_INT; | |
171 | ccfn = (u_long (*)())strtol; | |
172 | base = 0; | |
173 | break; | |
174 | ||
175 | case 'O': /* compat */ | |
176 | flags |= LONG; | |
177 | /* FALLTHROUGH */ | |
178 | case 'o': | |
179 | c = CT_INT; | |
180 | ccfn = strtoul; | |
181 | base = 8; | |
182 | break; | |
183 | ||
184 | case 'u': | |
185 | c = CT_INT; | |
186 | ccfn = strtoul; | |
187 | base = 10; | |
188 | break; | |
189 | ||
190 | case 'X': /* compat XXX */ | |
191 | flags |= LONG; | |
192 | /* FALLTHROUGH */ | |
193 | case 'x': | |
194 | flags |= PFXOK; /* enable 0x prefixing */ | |
195 | c = CT_INT; | |
196 | ccfn = strtoul; | |
197 | base = 16; | |
198 | break; | |
199 | ||
200 | #ifdef FLOATING_POINT | |
201 | case 'E': /* compat XXX */ | |
202 | case 'F': /* compat */ | |
203 | flags |= LONG; | |
204 | /* FALLTHROUGH */ | |
205 | case 'e': case 'f': case 'g': | |
206 | c = CT_FLOAT; | |
207 | break; | |
208 | #endif | |
209 | ||
210 | case 's': | |
211 | c = CT_STRING; | |
212 | break; | |
213 | ||
214 | case '[': | |
215 | fmt = __sccl(ccltab, fmt); | |
216 | flags |= NOSKIP; | |
217 | c = CT_CCL; | |
218 | break; | |
219 | ||
220 | case 'c': | |
221 | flags |= NOSKIP; | |
222 | c = CT_CHAR; | |
223 | break; | |
224 | ||
225 | case 'p': /* pointer format is like hex */ | |
226 | flags |= POINTER | PFXOK; | |
227 | c = CT_INT; | |
228 | ccfn = strtoul; | |
229 | base = 16; | |
230 | break; | |
231 | ||
232 | case 'n': | |
233 | if (flags & SUPPRESS) /* ??? */ | |
234 | continue; | |
235 | if (flags & SHORT) | |
236 | *va_arg(ap, short *) = nread; | |
237 | else if (flags & LONG) | |
238 | *va_arg(ap, long *) = nread; | |
87bdee5f | 239 | else |
3686044d | 240 | *va_arg(ap, int *) = nread; |
87bdee5f | 241 | continue; |
3686044d KB |
242 | |
243 | /* | |
244 | * Disgusting backwards compatibility hacks. XXX | |
245 | */ | |
246 | case '\0': /* compat */ | |
247 | return (EOF); | |
248 | ||
249 | default: /* compat */ | |
250 | if (isupper(c)) | |
251 | flags |= LONG; | |
252 | c = CT_INT; | |
253 | ccfn = (u_long (*)())strtol; | |
254 | base = 10; | |
255 | break; | |
256 | } | |
257 | ||
258 | /* | |
259 | * We have a conversion that requires input. | |
260 | */ | |
261 | if (fp->_r <= 0 && __srefill(fp)) | |
262 | goto input_failure; | |
263 | ||
264 | /* | |
265 | * Consume leading white space, except for formats | |
266 | * that suppress this. | |
267 | */ | |
268 | if ((flags & NOSKIP) == 0) { | |
269 | while (isspace(*fp->_p)) { | |
270 | nread++; | |
271 | if (--fp->_r > 0) | |
272 | fp->_p++; | |
273 | else if (__srefill(fp)) | |
274 | goto input_failure; | |
275 | } | |
276 | /* | |
277 | * Note that there is at least one character in | |
278 | * the buffer, so conversions that do not set NOSKIP | |
279 | * ca no longer result in an input failure. | |
280 | */ | |
281 | } | |
282 | ||
283 | /* | |
284 | * Do the conversion. | |
285 | */ | |
286 | switch (c) { | |
287 | ||
288 | case CT_CHAR: | |
289 | /* scan arbitrary characters (sets NOSKIP) */ | |
290 | if (width == 0) | |
291 | width = 1; | |
292 | if (flags & SUPPRESS) { | |
293 | size_t sum = 0; | |
294 | for (;;) { | |
295 | if ((n = fp->_r) < width) { | |
296 | sum += n; | |
297 | width -= n; | |
298 | fp->_p += n; | |
299 | if (__srefill(fp)) { | |
300 | if (sum == 0) | |
301 | goto input_failure; | |
302 | break; | |
303 | } | |
304 | } else { | |
305 | sum += width; | |
306 | fp->_r -= width; | |
307 | fp->_p += width; | |
308 | break; | |
309 | } | |
310 | } | |
311 | nread += sum; | |
312 | } else { | |
313 | size_t r = fread((void *)va_arg(ap, char *), 1, | |
314 | width, fp); | |
315 | ||
316 | if (r == 0) | |
317 | goto input_failure; | |
318 | nread += r; | |
319 | nassigned++; | |
320 | } | |
321 | break; | |
322 | ||
323 | case CT_CCL: | |
324 | /* scan a (nonempty) character class (sets NOSKIP) */ | |
325 | if (width == 0) | |
326 | width = ~0; /* `infinity' */ | |
327 | /* take only those things in the class */ | |
328 | if (flags & SUPPRESS) { | |
329 | n = 0; | |
330 | while (ccltab[*fp->_p]) { | |
331 | n++, fp->_r--, fp->_p++; | |
332 | if (--width == 0) | |
333 | break; | |
334 | if (fp->_r <= 0 && __srefill(fp)) { | |
335 | if (n == 0) | |
336 | goto input_failure; | |
337 | break; | |
338 | } | |
339 | } | |
340 | if (n == 0) | |
341 | goto match_failure; | |
342 | } else { | |
343 | p0 = p = va_arg(ap, char *); | |
344 | while (ccltab[*fp->_p]) { | |
345 | fp->_r--; | |
346 | *p++ = *fp->_p++; | |
347 | if (--width == 0) | |
348 | break; | |
349 | if (fp->_r <= 0 && __srefill(fp)) { | |
350 | if (p == p0) | |
351 | goto input_failure; | |
352 | break; | |
353 | } | |
354 | } | |
355 | n = p - p0; | |
356 | if (n == 0) | |
357 | goto match_failure; | |
358 | *p = 0; | |
359 | nassigned++; | |
360 | } | |
361 | nread += n; | |
362 | break; | |
363 | ||
364 | case CT_STRING: | |
365 | /* like CCL, but zero-length string OK, & no NOSKIP */ | |
366 | if (width == 0) | |
367 | width = ~0; | |
368 | if (flags & SUPPRESS) { | |
369 | n = 0; | |
370 | while (!isspace(*fp->_p)) { | |
371 | n++, fp->_r--, fp->_p++; | |
372 | if (--width == 0) | |
373 | break; | |
374 | if (fp->_r <= 0 && __srefill(fp)) | |
375 | break; | |
376 | } | |
377 | nread += n; | |
378 | } else { | |
379 | p0 = p = va_arg(ap, char *); | |
380 | while (!isspace(*fp->_p)) { | |
381 | fp->_r--; | |
382 | *p++ = *fp->_p++; | |
383 | if (--width == 0) | |
384 | break; | |
385 | if (fp->_r <= 0 && __srefill(fp)) | |
386 | break; | |
387 | } | |
388 | *p = 0; | |
389 | nread += p - p0; | |
390 | nassigned++; | |
391 | } | |
87bdee5f | 392 | continue; |
3686044d KB |
393 | |
394 | case CT_INT: | |
395 | /* scan an integer as if by strtol/strtoul */ | |
396 | #ifdef hardway | |
397 | if (width == 0 || width > sizeof(buf) - 1) | |
398 | width = sizeof(buf) - 1; | |
399 | #else | |
400 | /* size_t is unsigned, hence this optimisation */ | |
401 | if (--width > sizeof(buf) - 2) | |
402 | width = sizeof(buf) - 2; | |
403 | width++; | |
404 | #endif | |
405 | flags |= SIGNOK | NDIGITS | NZDIGITS; | |
406 | for (p = buf; width; width--) { | |
407 | c = *fp->_p; | |
408 | /* | |
409 | * Switch on the character; `goto ok' | |
410 | * if we accept it as a part of number. | |
411 | */ | |
412 | switch (c) { | |
413 | ||
414 | /* | |
415 | * The digit 0 is always legal, but is | |
416 | * special. For %i conversions, if no | |
417 | * digits (zero or nonzero) have been | |
418 | * scanned (only signs), we will have | |
419 | * base==0. In that case, we should set | |
420 | * it to 8 and enable 0x prefixing. | |
421 | * Also, if we have not scanned zero digits | |
422 | * before this, do not turn off prefixing | |
423 | * (someone else will turn it off if we | |
424 | * have scanned any nonzero digits). | |
425 | */ | |
426 | case '0': | |
427 | if (base == 0) { | |
428 | base = 8; | |
429 | flags |= PFXOK; | |
430 | } | |
431 | if (flags & NZDIGITS) | |
432 | flags &= ~(SIGNOK|NZDIGITS|NDIGITS); | |
433 | else | |
434 | flags &= ~(SIGNOK|PFXOK|NDIGITS); | |
435 | goto ok; | |
436 | ||
437 | /* 1 through 7 always legal */ | |
438 | case '1': case '2': case '3': | |
439 | case '4': case '5': case '6': case '7': | |
440 | base = basefix[base]; | |
441 | flags &= ~(SIGNOK | PFXOK | NDIGITS); | |
442 | goto ok; | |
443 | ||
444 | /* digits 8 and 9 ok iff decimal or hex */ | |
445 | case '8': case '9': | |
446 | base = basefix[base]; | |
447 | if (base <= 8) | |
448 | break; /* not legal here */ | |
449 | flags &= ~(SIGNOK | PFXOK | NDIGITS); | |
450 | goto ok; | |
451 | ||
452 | /* letters ok iff hex */ | |
453 | case 'A': case 'B': case 'C': | |
454 | case 'D': case 'E': case 'F': | |
455 | case 'a': case 'b': case 'c': | |
456 | case 'd': case 'e': case 'f': | |
457 | /* no need to fix base here */ | |
458 | if (base <= 10) | |
459 | break; /* not legal here */ | |
460 | flags &= ~(SIGNOK | PFXOK | NDIGITS); | |
461 | goto ok; | |
462 | ||
463 | /* sign ok only as first character */ | |
464 | case '+': case '-': | |
465 | if (flags & SIGNOK) { | |
466 | flags &= ~SIGNOK; | |
467 | goto ok; | |
468 | } | |
469 | break; | |
470 | ||
471 | /* x ok iff flag still set & 2nd char */ | |
472 | case 'x': case 'X': | |
473 | if (flags & PFXOK && p == buf + 1) { | |
474 | base = 16; /* if %i */ | |
475 | flags &= ~PFXOK; | |
476 | goto ok; | |
477 | } | |
478 | break; | |
479 | } | |
480 | ||
481 | /* | |
482 | * If we got here, c is not a legal character | |
483 | * for a number. Stop accumulating digits. | |
484 | */ | |
87bdee5f | 485 | break; |
3686044d KB |
486 | ok: |
487 | /* | |
488 | * c is legal: store it and look at the next. | |
489 | */ | |
490 | *p++ = c; | |
491 | if (--fp->_r > 0) | |
492 | fp->_p++; | |
493 | else if (__srefill(fp)) | |
494 | break; /* EOF */ | |
495 | } | |
496 | /* | |
497 | * If we had only a sign, it is no good; push | |
498 | * back the sign. If the number ends in `x', | |
499 | * it was [sign] '0' 'x', so push back the x | |
500 | * and treat it as [sign] '0'. | |
501 | */ | |
502 | if (flags & NDIGITS) { | |
503 | if (p > buf) | |
504 | (void) ungetc(*(u_char *)--p, fp); | |
505 | goto match_failure; | |
506 | } | |
507 | c = ((u_char *)p)[-1]; | |
508 | if (c == 'x' || c == 'X') { | |
509 | --p; | |
510 | (void) ungetc(c, fp); | |
511 | } | |
512 | if ((flags & SUPPRESS) == 0) { | |
513 | u_long res; | |
514 | ||
515 | *p = 0; | |
516 | res = (*ccfn)(buf, (char **)NULL, base); | |
517 | if (flags & POINTER) | |
518 | *va_arg(ap, void **) = (void *)res; | |
519 | else if (flags & SHORT) | |
520 | *va_arg(ap, short *) = res; | |
521 | else if (flags & LONG) | |
522 | *va_arg(ap, long *) = res; | |
523 | else | |
524 | *va_arg(ap, int *) = res; | |
525 | nassigned++; | |
526 | } | |
527 | nread += p - buf; | |
528 | break; | |
529 | ||
530 | #ifdef FLOATING_POINT | |
531 | case CT_FLOAT: | |
532 | /* scan a floating point number as if by strtod */ | |
533 | #ifdef hardway | |
534 | if (width == 0 || width > sizeof(buf) - 1) | |
535 | width = sizeof(buf) - 1; | |
536 | #else | |
537 | /* size_t is unsigned, hence this optimisation */ | |
538 | if (--width > sizeof(buf) - 2) | |
539 | width = sizeof(buf) - 2; | |
540 | width++; | |
541 | #endif | |
542 | flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; | |
543 | for (p = buf; width; width--) { | |
544 | c = *fp->_p; | |
545 | /* | |
546 | * This code mimicks the integer conversion | |
547 | * code, but is much simpler. | |
548 | */ | |
549 | switch (c) { | |
550 | ||
551 | case '0': case '1': case '2': case '3': | |
552 | case '4': case '5': case '6': case '7': | |
553 | case '8': case '9': | |
554 | flags &= ~(SIGNOK | NDIGITS); | |
555 | goto fok; | |
556 | ||
557 | case '+': case '-': | |
558 | if (flags & SIGNOK) { | |
559 | flags &= ~SIGNOK; | |
560 | goto fok; | |
561 | } | |
562 | break; | |
563 | case '.': | |
564 | if (flags & DPTOK) { | |
565 | flags &= ~(SIGNOK | DPTOK); | |
566 | goto fok; | |
567 | } | |
568 | break; | |
569 | case 'e': case 'E': | |
570 | /* no exponent without some digits */ | |
571 | if ((flags&(NDIGITS|EXPOK)) == EXPOK) { | |
572 | flags = | |
573 | (flags & ~(EXPOK|DPTOK)) | | |
574 | SIGNOK | NDIGITS; | |
575 | goto fok; | |
576 | } | |
577 | break; | |
578 | } | |
87bdee5f | 579 | break; |
3686044d KB |
580 | fok: |
581 | *p++ = c; | |
582 | if (--fp->_r > 0) | |
583 | fp->_p++; | |
584 | else if (__srefill(fp)) | |
585 | break; /* EOF */ | |
586 | } | |
587 | /* | |
588 | * If no digits, might be missing exponent digits | |
589 | * (just give back the exponent) or might be missing | |
590 | * regular digits, but had sign and/or decimal point. | |
591 | */ | |
592 | if (flags & NDIGITS) { | |
593 | if (flags & EXPOK) { | |
594 | /* no digits at all */ | |
595 | while (p > buf) | |
596 | ungetc(*(u_char *)--p, fp); | |
597 | goto match_failure; | |
598 | } | |
599 | /* just a bad exponent (e and maybe sign) */ | |
600 | c = *(u_char *)--p; | |
601 | if (c != 'e' && c != 'E') { | |
602 | (void) ungetc(c, fp);/* sign */ | |
603 | c = *(u_char *)--p; | |
604 | } | |
605 | (void) ungetc(c, fp); | |
606 | } | |
607 | if ((flags & SUPPRESS) == 0) { | |
608 | double res; | |
609 | ||
610 | *p = 0; | |
611 | res = atof(buf); | |
612 | if (flags & LONG) | |
613 | *va_arg(ap, double *) = res; | |
614 | else | |
615 | *va_arg(ap, float *) = res; | |
616 | nassigned++; | |
617 | } | |
618 | nread += p - buf; | |
87bdee5f | 619 | break; |
3686044d KB |
620 | #endif /* FLOATING_POINT */ |
621 | } | |
87bdee5f | 622 | } |
3686044d KB |
623 | input_failure: |
624 | return (nassigned ? nassigned : -1); | |
625 | match_failure: | |
626 | return (nassigned); | |
87bdee5f KM |
627 | } |
628 | ||
3686044d KB |
629 | /* |
630 | * Fill in the given table from the scanset at the given format | |
631 | * (just after `['). Return a pointer to the character past the | |
632 | * closing `]'. The table has a 1 wherever characters should be | |
633 | * considered part of the scanset. | |
634 | */ | |
635 | static u_char * | |
636 | __sccl(tab, fmt) | |
637 | register char *tab; | |
638 | register u_char *fmt; | |
87bdee5f | 639 | { |
3686044d KB |
640 | register int c, n, v; |
641 | ||
642 | /* first `clear' the whole table */ | |
643 | c = *fmt++; /* first char hat => negated scanset */ | |
644 | if (c == '^') { | |
645 | v = 1; /* default => accept */ | |
646 | c = *fmt++; /* get new first char */ | |
87bdee5f | 647 | } else |
3686044d KB |
648 | v = 0; /* default => reject */ |
649 | /* should probably use memset here */ | |
650 | for (n = 0; n < 256; n++) | |
651 | tab[n] = v; | |
652 | if (c == 0) | |
653 | return (fmt - 1);/* format ended before closing ] */ | |
87bdee5f | 654 | |
3686044d KB |
655 | /* |
656 | * Now set the entries corresponding to the actual scanset | |
657 | * to the opposite of the above. | |
658 | * | |
659 | * The first character may be ']' (or '-') without being special; | |
660 | * the last character may be '-'. | |
661 | */ | |
662 | v = 1 - v; | |
663 | for (;;) { | |
664 | tab[c] = v; /* take character c */ | |
665 | doswitch: | |
666 | n = *fmt++; /* and examine the next */ | |
667 | switch (n) { | |
87bdee5f | 668 | |
3686044d KB |
669 | case 0: /* format ended too soon */ |
670 | return (fmt - 1); | |
671 | ||
672 | case '-': | |
673 | /* | |
674 | * A scanset of the form | |
675 | * [01+-] | |
676 | * is defined as `the digit 0, the digit 1, | |
677 | * the character +, the character -', but | |
678 | * the effect of a scanset such as | |
679 | * [a-zA-Z0-9] | |
680 | * is implementation defined. The V7 Unix | |
681 | * scanf treats `a-z' as `the letters a through | |
682 | * z', but treats `a-a' as `the letter a, the | |
683 | * character -, and the letter a'. | |
684 | * | |
685 | * For compatibility, the `-' is not considerd | |
686 | * to define a range if the character following | |
687 | * it is either a close bracket (required by ANSI) | |
688 | * or is not numerically greater than the character | |
689 | * we just stored in the table (c). | |
690 | */ | |
691 | n = *fmt; | |
692 | if (n == ']' || n < c) { | |
693 | c = '-'; | |
694 | break; /* resume the for(;;) */ | |
695 | } | |
696 | fmt++; | |
697 | do { /* fill in the range */ | |
698 | tab[++c] = v; | |
699 | } while (c < n); | |
700 | #if 1 /* XXX another disgusting compatibility hack */ | |
701 | /* | |
702 | * Alas, the V7 Unix scanf also treats formats | |
703 | * such as [a-c-e] as `the letters a through e'. | |
704 | * This too is permitted by the standard.... | |
705 | */ | |
706 | goto doswitch; | |
707 | #else | |
708 | c = *fmt++; | |
709 | if (c == 0) | |
710 | return (fmt - 1); | |
711 | if (c == ']') | |
712 | return (fmt); | |
713 | #endif | |
714 | break; | |
715 | ||
716 | case ']': /* end of scanset */ | |
717 | return (fmt); | |
718 | ||
719 | default: /* just another character */ | |
720 | c = n; | |
721 | break; | |
722 | } | |
87bdee5f | 723 | } |
3686044d | 724 | /* NOTREACHED */ |
87bdee5f | 725 | } |