1 /*
2 * Copyright (c) 2000-2001, 2004 Proofpoint, Inc. and its suppliers.
3 * All rights reserved.
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * By using this file, you agree to the terms and conditions set
11 * forth in the LICENSE file which can be found at the top level of
12 * the sendmail distribution.
13 */
14
15 #include <sm/gen.h>
16 SM_IDSTR(id, "@(#)$Id: vfscanf.c,v 1.55 2013-11-22 20:51:44 ca Exp $")
17
18 #include <ctype.h>
19 #include <stdlib.h>
20 #include <errno.h>
21 #include <setjmp.h>
22 #include <sm/time.h>
23 #include <sm/varargs.h>
24 #include <sm/config.h>
25 #include <sm/io.h>
26 #include <sm/signal.h>
27 #include <sm/clock.h>
28 #include <sm/string.h>
29 #include "local.h"
30
31 #define BUF 513 /* Maximum length of numeric string. */
32
33 /* Flags used during conversion. */
34 #define LONG 0x01 /* l: long or double */
35 #define SHORT 0x04 /* h: short */
36 #define QUAD 0x08 /* q: quad (same as ll) */
37 #define SUPPRESS 0x10 /* suppress assignment */
38 #define POINTER 0x20 /* weird %p pointer (`fake hex') */
39 #define NOSKIP 0x40 /* do not skip blanks */
40
41 /*
42 ** The following are used in numeric conversions only:
43 ** SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
44 ** SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
45 */
46
47 #define SIGNOK 0x080 /* +/- is (still) legal */
48 #define NDIGITS 0x100 /* no digits detected */
49
50 #define DPTOK 0x200 /* (float) decimal point is still legal */
51 #define EXPOK 0x400 /* (float) exponent (e+3, etc) still legal */
52
53 #define PFXOK 0x200 /* 0x prefix is (still) legal */
54 #define NZDIGITS 0x400 /* no zero digits detected */
55
56 /* Conversion types. */
57 #define CT_CHAR 0 /* %c conversion */
58 #define CT_CCL 1 /* %[...] conversion */
59 #define CT_STRING 2 /* %s conversion */
60 #define CT_INT 3 /* integer, i.e., strtoll or strtoull */
61 #define CT_FLOAT 4 /* floating, i.e., strtod */
62
63 static void scanalrm __P((int));
64 static unsigned char *sm_sccl __P((char *, unsigned char *));
65 static jmp_buf ScanTimeOut;
66
67 /*
68 ** SCANALRM -- handler when timeout activated for sm_io_vfscanf()
69 **
70 ** Returns flow of control to where setjmp(ScanTimeOut) was set.
71 **
72 ** Parameters:
73 ** sig -- unused
74 **
75 ** Returns:
76 ** does not return
77 **
78 ** Side Effects:
79 ** returns flow of control to setjmp(ScanTimeOut).
80 **
81 ** NOTE: THIS CAN BE CALLED FROM A SIGNAL HANDLER. DO NOT ADD
82 ** ANYTHING TO THIS ROUTINE UNLESS YOU KNOW WHAT YOU ARE
83 ** DOING.
84 */
85
86 /* ARGSUSED0 */
87 static void
scanalrm(sig)88 scanalrm(sig)
89 int sig;
90 {
91 longjmp(ScanTimeOut, 1);
92 }
93
94 /*
95 ** SM_VFSCANF -- convert input into data units
96 **
97 ** Parameters:
98 ** fp -- file pointer for input data
99 ** timeout -- time intvl allowed to complete (milliseconds)
100 ** fmt0 -- format for finding data units
101 ** ap -- vectors for memory location for storing data units
102 **
103 ** Results:
104 ** Success: number of data units assigned
105 ** Failure: SM_IO_EOF
106 */
107
108 int
sm_vfscanf(fp,timeout,fmt0,ap)109 sm_vfscanf(fp, timeout, fmt0, ap)
110 register SM_FILE_T *fp;
111 int SM_NONVOLATILE timeout;
112 char const *fmt0;
113 va_list ap;
114 {
115 register unsigned char *SM_NONVOLATILE fmt = (unsigned char *) fmt0;
116 register int c; /* character from format, or conversion */
117 register size_t width; /* field width, or 0 */
118 register char *p; /* points into all kinds of strings */
119 register int n; /* handy integer */
120 register int flags; /* flags as defined above */
121 register char *p0; /* saves original value of p when necessary */
122 int nassigned; /* number of fields assigned */
123 int nread; /* number of characters consumed from fp */
124 int base; /* base argument to strtoll/strtoull */
125
126 /* conversion function (strtoll/strtoull) */
127 ULONGLONG_T (*ccfn) __P((const char *, char **, int));
128 char ccltab[256]; /* character class table for %[...] */
129 char buf[BUF]; /* buffer for numeric conversions */
130 SM_EVENT *evt = NULL;
131
132 /* `basefix' is used to avoid `if' tests in the integer scanner */
133 static short basefix[17] =
134 { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
135
136 if (timeout == SM_TIME_DEFAULT)
137 timeout = fp->f_timeout;
138 if (timeout == SM_TIME_IMMEDIATE)
139 {
140 /*
141 ** Filling the buffer will take time and we are wanted to
142 ** return immediately. So...
143 */
144
145 errno = EAGAIN;
146 return SM_IO_EOF;
147 }
148
149 if (timeout != SM_TIME_FOREVER)
150 {
151 if (setjmp(ScanTimeOut) != 0)
152 {
153 errno = EAGAIN;
154 return SM_IO_EOF;
155 }
156
157 evt = sm_seteventm(timeout, scanalrm, 0);
158 }
159
160 nassigned = 0;
161 nread = 0;
162 base = 0; /* XXX just to keep gcc happy */
163 ccfn = NULL; /* XXX just to keep gcc happy */
164 for (;;)
165 {
166 c = *fmt++;
167 if (c == 0)
168 {
169 if (evt != NULL)
170 sm_clrevent(evt); /* undo our timeout */
171 return nassigned;
172 }
173 if (isspace(c))
174 {
175 while ((fp->f_r > 0 || sm_refill(fp, SM_TIME_FOREVER)
176 == 0) &&
177 isspace(*fp->f_p))
178 nread++, fp->f_r--, fp->f_p++;
179 continue;
180 }
181 if (c != '%')
182 goto literal;
183 width = 0;
184 flags = 0;
185
186 /*
187 ** switch on the format. continue if done;
188 ** break once format type is derived.
189 */
190
191 again: c = *fmt++;
192 switch (c)
193 {
194 case '%':
195 literal:
196 if (fp->f_r <= 0 && sm_refill(fp, SM_TIME_FOREVER))
197 goto input_failure;
198 if (*fp->f_p != c)
199 goto match_failure;
200 fp->f_r--, fp->f_p++;
201 nread++;
202 continue;
203
204 case '*':
205 flags |= SUPPRESS;
206 goto again;
207 case 'h':
208 flags |= SHORT;
209 goto again;
210 case 'l':
211 if (*fmt == 'l')
212 {
213 fmt++;
214 flags |= QUAD;
215 }
216 else
217 {
218 flags |= LONG;
219 }
220 goto again;
221 case 'q':
222 flags |= QUAD;
223 goto again;
224
225 case '0': case '1': case '2': case '3': case '4':
226 case '5': case '6': case '7': case '8': case '9':
227 width = width * 10 + c - '0';
228 goto again;
229
230 /*
231 ** Conversions.
232 ** Those marked `compat' are for 4.[123]BSD compatibility.
233 **
234 ** (According to ANSI, E and X formats are supposed
235 ** to the same as e and x. Sorry about that.)
236 */
237
238 case 'D': /* compat */
239 flags |= LONG;
240 /* FALLTHROUGH */
241 case 'd':
242 c = CT_INT;
243 ccfn = (ULONGLONG_T (*)())sm_strtoll;
244 base = 10;
245 break;
246
247 case 'i':
248 c = CT_INT;
249 ccfn = (ULONGLONG_T (*)())sm_strtoll;
250 base = 0;
251 break;
252
253 case 'O': /* compat */
254 flags |= LONG;
255 /* FALLTHROUGH */
256 case 'o':
257 c = CT_INT;
258 ccfn = sm_strtoull;
259 base = 8;
260 break;
261
262 case 'u':
263 c = CT_INT;
264 ccfn = sm_strtoull;
265 base = 10;
266 break;
267
268 case 'X':
269 case 'x':
270 flags |= PFXOK; /* enable 0x prefixing */
271 c = CT_INT;
272 ccfn = sm_strtoull;
273 base = 16;
274 break;
275
276 case 'E':
277 case 'G':
278 case 'e':
279 case 'f':
280 case 'g':
281 c = CT_FLOAT;
282 break;
283
284 case 's':
285 c = CT_STRING;
286 break;
287
288 case '[':
289 fmt = sm_sccl(ccltab, fmt);
290 flags |= NOSKIP;
291 c = CT_CCL;
292 break;
293
294 case 'c':
295 flags |= NOSKIP;
296 c = CT_CHAR;
297 break;
298
299 case 'p': /* pointer format is like hex */
300 flags |= POINTER | PFXOK;
301 c = CT_INT;
302 ccfn = sm_strtoull;
303 base = 16;
304 break;
305
306 case 'n':
307 if (flags & SUPPRESS) /* ??? */
308 continue;
309 if (flags & SHORT)
310 *SM_VA_ARG(ap, short *) = nread;
311 else if (flags & LONG)
312 *SM_VA_ARG(ap, long *) = nread;
313 else
314 *SM_VA_ARG(ap, int *) = nread;
315 continue;
316
317 /* Disgusting backwards compatibility hacks. XXX */
318 case '\0': /* compat */
319 if (evt != NULL)
320 sm_clrevent(evt); /* undo our timeout */
321 return SM_IO_EOF;
322
323 default: /* compat */
324 if (isupper(c))
325 flags |= LONG;
326 c = CT_INT;
327 ccfn = (ULONGLONG_T (*)()) sm_strtoll;
328 base = 10;
329 break;
330 }
331
332 /* We have a conversion that requires input. */
333 if (fp->f_r <= 0 && sm_refill(fp, SM_TIME_FOREVER))
334 goto input_failure;
335
336 /*
337 ** Consume leading white space, except for formats
338 ** that suppress this.
339 */
340
341 if ((flags & NOSKIP) == 0)
342 {
343 while (isspace(*fp->f_p))
344 {
345 nread++;
346 if (--fp->f_r > 0)
347 fp->f_p++;
348 else if (sm_refill(fp, SM_TIME_FOREVER))
349 goto input_failure;
350 }
351 /*
352 ** Note that there is at least one character in
353 ** the buffer, so conversions that do not set NOSKIP
354 ** can no longer result in an input failure.
355 */
356 }
357
358 /* Do the conversion. */
359 switch (c)
360 {
361 case CT_CHAR:
362 /* scan arbitrary characters (sets NOSKIP) */
363 if (width == 0)
364 width = 1;
365 if (flags & SUPPRESS)
366 {
367 size_t sum = 0;
368 for (;;)
369 {
370 if ((size_t) (n = fp->f_r) < width)
371 {
372 sum += n;
373 width -= n;
374 fp->f_p += n;
375 if (sm_refill(fp,
376 SM_TIME_FOREVER))
377 {
378 if (sum == 0)
379 goto input_failure;
380 break;
381 }
382 }
383 else
384 {
385 sum += width;
386 fp->f_r -= width;
387 fp->f_p += width;
388 break;
389 }
390 }
391 nread += sum;
392 }
393 else
394 {
395 size_t r;
396
397 r = sm_io_read(fp, SM_TIME_FOREVER,
398 (void *) SM_VA_ARG(ap, char *),
399 width);
400 if (r == 0)
401 goto input_failure;
402 nread += r;
403 nassigned++;
404 }
405 break;
406
407 case CT_CCL:
408 /* scan a (nonempty) character class (sets NOSKIP) */
409 if (width == 0)
410 width = (size_t)~0; /* `infinity' */
411
412 /* take only those things in the class */
413 if (flags & SUPPRESS)
414 {
415 n = 0;
416 while (ccltab[*fp->f_p] != '\0')
417 {
418 n++, fp->f_r--, fp->f_p++;
419 if (--width == 0)
420 break;
421 if (fp->f_r <= 0 &&
422 sm_refill(fp, SM_TIME_FOREVER))
423 {
424 if (n == 0) /* XXX how? */
425 goto input_failure;
426 break;
427 }
428 }
429 if (n == 0)
430 goto match_failure;
431 }
432 else
433 {
434 p0 = p = SM_VA_ARG(ap, char *);
435 while (ccltab[*fp->f_p] != '\0')
436 {
437 fp->f_r--;
438 *p++ = *fp->f_p++;
439 if (--width == 0)
440 break;
441 if (fp->f_r <= 0 &&
442 sm_refill(fp, SM_TIME_FOREVER))
443 {
444 if (p == p0)
445 goto input_failure;
446 break;
447 }
448 }
449 n = p - p0;
450 if (n == 0)
451 goto match_failure;
452 *p = 0;
453 nassigned++;
454 }
455 nread += n;
456 break;
457
458 case CT_STRING:
459 /* like CCL, but zero-length string OK, & no NOSKIP */
460 if (width == 0)
461 width = (size_t)~0;
462 if (flags & SUPPRESS)
463 {
464 n = 0;
465 while (!isspace(*fp->f_p))
466 {
467 n++, fp->f_r--, fp->f_p++;
468 if (--width == 0)
469 break;
470 if (fp->f_r <= 0 &&
471 sm_refill(fp, SM_TIME_FOREVER))
472 break;
473 }
474 nread += n;
475 }
476 else
477 {
478 p0 = p = SM_VA_ARG(ap, char *);
479 while (!isspace(*fp->f_p))
480 {
481 fp->f_r--;
482 *p++ = *fp->f_p++;
483 if (--width == 0)
484 break;
485 if (fp->f_r <= 0 &&
486 sm_refill(fp, SM_TIME_FOREVER))
487 break;
488 }
489 *p = 0;
490 nread += p - p0;
491 nassigned++;
492 }
493 continue;
494
495 case CT_INT:
496 /* scan an integer as if by strtoll/strtoull */
497 #if SM_CONF_BROKEN_SIZE_T
498 if (width == 0 || width > sizeof(buf) - 1)
499 width = sizeof(buf) - 1;
500 #else /* SM_CONF_BROKEN_SIZE_T */
501 /* size_t is unsigned, hence this optimisation */
502 if (--width > sizeof(buf) - 2)
503 width = sizeof(buf) - 2;
504 width++;
505 #endif /* SM_CONF_BROKEN_SIZE_T */
506 flags |= SIGNOK | NDIGITS | NZDIGITS;
507 for (p = buf; width > 0; width--)
508 {
509 c = *fp->f_p;
510
511 /*
512 ** Switch on the character; `goto ok'
513 ** if we accept it as a part of number.
514 */
515
516 switch (c)
517 {
518
519 /*
520 ** The digit 0 is always legal, but is
521 ** special. For %i conversions, if no
522 ** digits (zero or nonzero) have been
523 ** scanned (only signs), we will have
524 ** base==0. In that case, we should set
525 ** it to 8 and enable 0x prefixing.
526 ** Also, if we have not scanned zero digits
527 ** before this, do not turn off prefixing
528 ** (someone else will turn it off if we
529 ** have scanned any nonzero digits).
530 */
531
532 case '0':
533 if (base == 0)
534 {
535 base = 8;
536 flags |= PFXOK;
537 }
538 if (flags & NZDIGITS)
539 flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
540 else
541 flags &= ~(SIGNOK|PFXOK|NDIGITS);
542 goto ok;
543
544 /* 1 through 7 always legal */
545 case '1': case '2': case '3':
546 case '4': case '5': case '6': case '7':
547 base = basefix[base];
548 flags &= ~(SIGNOK | PFXOK | NDIGITS);
549 goto ok;
550
551 /* digits 8 and 9 ok iff decimal or hex */
552 case '8': case '9':
553 base = basefix[base];
554 if (base <= 8)
555 break; /* not legal here */
556 flags &= ~(SIGNOK | PFXOK | NDIGITS);
557 goto ok;
558
559 /* letters ok iff hex */
560 case 'A': case 'B': case 'C':
561 case 'D': case 'E': case 'F':
562 case 'a': case 'b': case 'c':
563 case 'd': case 'e': case 'f':
564
565 /* no need to fix base here */
566 if (base <= 10)
567 break; /* not legal here */
568 flags &= ~(SIGNOK | PFXOK | NDIGITS);
569 goto ok;
570
571 /* sign ok only as first character */
572 case '+': case '-':
573 if (flags & SIGNOK)
574 {
575 flags &= ~SIGNOK;
576 goto ok;
577 }
578 break;
579
580 /* x ok iff flag still set & 2nd char */
581 case 'x': case 'X':
582 if (flags & PFXOK && p == buf + 1)
583 {
584 base = 16; /* if %i */
585 flags &= ~PFXOK;
586 goto ok;
587 }
588 break;
589 }
590
591 /*
592 ** If we got here, c is not a legal character
593 ** for a number. Stop accumulating digits.
594 */
595
596 break;
597 ok:
598 /* c is legal: store it and look at the next. */
599 *p++ = c;
600 if (--fp->f_r > 0)
601 fp->f_p++;
602 else if (sm_refill(fp, SM_TIME_FOREVER))
603 break; /* SM_IO_EOF */
604 }
605
606 /*
607 ** If we had only a sign, it is no good; push
608 ** back the sign. If the number ends in `x',
609 ** it was [sign] '0' 'x', so push back the x
610 ** and treat it as [sign] '0'.
611 */
612
613 if (flags & NDIGITS)
614 {
615 if (p > buf)
616 (void) sm_io_ungetc(fp, SM_TIME_DEFAULT,
617 *(unsigned char *)--p);
618 goto match_failure;
619 }
620 c = ((unsigned char *)p)[-1];
621 if (c == 'x' || c == 'X')
622 {
623 --p;
624 (void) sm_io_ungetc(fp, SM_TIME_DEFAULT, c);
625 }
626 if ((flags & SUPPRESS) == 0)
627 {
628 ULONGLONG_T res;
629
630 *p = 0;
631 res = (*ccfn)(buf, (char **)NULL, base);
632 if (flags & POINTER)
633 *SM_VA_ARG(ap, void **) =
634 (void *)(long) res;
635 else if (flags & QUAD)
636 *SM_VA_ARG(ap, LONGLONG_T *) = res;
637 else if (flags & LONG)
638 *SM_VA_ARG(ap, long *) = res;
639 else if (flags & SHORT)
640 *SM_VA_ARG(ap, short *) = res;
641 else
642 *SM_VA_ARG(ap, int *) = res;
643 nassigned++;
644 }
645 nread += p - buf;
646 break;
647
648 case CT_FLOAT:
649 /* scan a floating point number as if by strtod */
650 if (width == 0 || width > sizeof(buf) - 1)
651 width = sizeof(buf) - 1;
652 flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
653 for (p = buf; width; width--)
654 {
655 c = *fp->f_p;
656
657 /*
658 ** This code mimics the integer conversion
659 ** code, but is much simpler.
660 */
661
662 switch (c)
663 {
664
665 case '0': case '1': case '2': case '3':
666 case '4': case '5': case '6': case '7':
667 case '8': case '9':
668 flags &= ~(SIGNOK | NDIGITS);
669 goto fok;
670
671 case '+': case '-':
672 if (flags & SIGNOK)
673 {
674 flags &= ~SIGNOK;
675 goto fok;
676 }
677 break;
678 case '.':
679 if (flags & DPTOK)
680 {
681 flags &= ~(SIGNOK | DPTOK);
682 goto fok;
683 }
684 break;
685 case 'e': case 'E':
686
687 /* no exponent without some digits */
688 if ((flags&(NDIGITS|EXPOK)) == EXPOK)
689 {
690 flags =
691 (flags & ~(EXPOK|DPTOK)) |
692 SIGNOK | NDIGITS;
693 goto fok;
694 }
695 break;
696 }
697 break;
698 fok:
699 *p++ = c;
700 if (--fp->f_r > 0)
701 fp->f_p++;
702 else if (sm_refill(fp, SM_TIME_FOREVER))
703 break; /* SM_IO_EOF */
704 }
705
706 /*
707 ** If no digits, might be missing exponent digits
708 ** (just give back the exponent) or might be missing
709 ** regular digits, but had sign and/or decimal point.
710 */
711
712 if (flags & NDIGITS)
713 {
714 if (flags & EXPOK)
715 {
716 /* no digits at all */
717 while (p > buf)
718 (void) sm_io_ungetc(fp,
719 SM_TIME_DEFAULT,
720 *(unsigned char *)--p);
721 goto match_failure;
722 }
723
724 /* just a bad exponent (e and maybe sign) */
725 c = *(unsigned char *) --p;
726 if (c != 'e' && c != 'E')
727 {
728 (void) sm_io_ungetc(fp, SM_TIME_DEFAULT,
729 c); /* sign */
730 c = *(unsigned char *)--p;
731 }
732 (void) sm_io_ungetc(fp, SM_TIME_DEFAULT, c);
733 }
734 if ((flags & SUPPRESS) == 0)
735 {
736 double res;
737
738 *p = 0;
739 res = strtod(buf, (char **) NULL);
740 if (flags & LONG)
741 *SM_VA_ARG(ap, double *) = res;
742 else
743 *SM_VA_ARG(ap, float *) = res;
744 nassigned++;
745 }
746 nread += p - buf;
747 break;
748 }
749 }
750 input_failure:
751 if (evt != NULL)
752 sm_clrevent(evt); /* undo our timeout */
753 return nassigned ? nassigned : -1;
754 match_failure:
755 if (evt != NULL)
756 sm_clrevent(evt); /* undo our timeout */
757 return nassigned;
758 }
759
760 /*
761 ** SM_SCCL -- sequenced character comparison list
762 **
763 ** Fill in the given table from the scanset at the given format
764 ** (just after `['). Return a pointer to the character past the
765 ** closing `]'. The table has a 1 wherever characters should be
766 ** considered part of the scanset.
767 **
768 ** Parameters:
769 ** tab -- array flagging "active" char's to match (returned)
770 ** fmt -- character list (within "[]")
771 **
772 ** Results:
773 */
774
775 static unsigned char *
sm_sccl(tab,fmt)776 sm_sccl(tab, fmt)
777 register char *tab;
778 register unsigned char *fmt;
779 {
780 register int c, n, v;
781
782 /* first `clear' the whole table */
783 c = *fmt++; /* first char hat => negated scanset */
784 if (c == '^')
785 {
786 v = 1; /* default => accept */
787 c = *fmt++; /* get new first char */
788 }
789 else
790 v = 0; /* default => reject */
791
792 /* should probably use memset here */
793 for (n = 0; n < 256; n++)
794 tab[n] = v;
795 if (c == 0)
796 return fmt - 1; /* format ended before closing ] */
797
798 /*
799 ** Now set the entries corresponding to the actual scanset
800 ** to the opposite of the above.
801 **
802 ** The first character may be ']' (or '-') without being special;
803 ** the last character may be '-'.
804 */
805
806 v = 1 - v;
807 for (;;)
808 {
809 tab[c] = v; /* take character c */
810 doswitch:
811 n = *fmt++; /* and examine the next */
812 switch (n)
813 {
814
815 case 0: /* format ended too soon */
816 return fmt - 1;
817
818 case '-':
819 /*
820 ** A scanset of the form
821 ** [01+-]
822 ** is defined as `the digit 0, the digit 1,
823 ** the character +, the character -', but
824 ** the effect of a scanset such as
825 ** [a-zA-Z0-9]
826 ** is implementation defined. The V7 Unix
827 ** scanf treats `a-z' as `the letters a through
828 ** z', but treats `a-a' as `the letter a, the
829 ** character -, and the letter a'.
830 **
831 ** For compatibility, the `-' is not considered
832 ** to define a range if the character following
833 ** it is either a close bracket (required by ANSI)
834 ** or is not numerically greater than the character
835 ** we just stored in the table (c).
836 */
837
838 n = *fmt;
839 if (n == ']' || n < c)
840 {
841 c = '-';
842 break; /* resume the for(;;) */
843 }
844 fmt++;
845 do
846 {
847 /* fill in the range */
848 tab[++c] = v;
849 } while (c < n);
850 #if 1 /* XXX another disgusting compatibility hack */
851
852 /*
853 ** Alas, the V7 Unix scanf also treats formats
854 ** such as [a-c-e] as `the letters a through e'.
855 ** This too is permitted by the standard....
856 */
857
858 goto doswitch;
859 #else
860 c = *fmt++;
861 if (c == 0)
862 return fmt - 1;
863 if (c == ']')
864 return fmt;
865 break;
866 #endif
867
868 case ']': /* end of scanset */
869 return fmt;
870
871 default: /* just another character */
872 c = n;
873 break;
874 }
875 }
876 /* NOTREACHED */
877 }
878