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comparison mcabber/src/utils.c @ 803:8f8d8f8157a2

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Take care of the strcasestr lacking (Cygwin)
author Soren Andersen <somian@pobox.com>
date Mon, 10 Apr 2006 23:30:39 +0200
parents dd860da62002
children a6628f0aabc1
comparison
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802:dd860da62002 803:8f8d8f8157a2
508 508
509 return xtext; 509 return xtext;
510 } 510 }
511 511
512 512
513 /* Cygwin's newlib does not have strcasestr() */
514 /* The author of the code before the endif is
515 * Jeffrey Stedfast <fejj@ximian.com>
516 * and this code is reusable in compliance with the GPL v2. -- somian */
517
518 #if !defined(HAVE_STRCASESTR)
519
520 # define lowercase(c) (isupper ((int) (c)) ? tolower ((int) (c)) : (int) (c))
521 # define bm_index(c, icase) ((icase) ? lowercase (c) : (int) (c))
522 # define bm_equal(c1, c2, icase) ((icase) ? lowercase (c1) == lowercase (c2) : (c1) == (c2))
523
524 /* FIXME: this is just a guess... should really do some performace tests to get an accurate measure */
525 # define bm_optimal(hlen, nlen) (((hlen) ? (hlen) > 20 : 1) && (nlen) > 10 ? 1 : 0)
526
527 static unsigned char *
528 __boyer_moore (const unsigned char *haystack, size_t haystacklen,
529 const unsigned char *needle, size_t needlelen, int icase)
530 {
531 register unsigned char *hc_ptr, *nc_ptr;
532 unsigned char *he_ptr, *ne_ptr, *h_ptr;
533 size_t skiptable[256], n;
534 register int i;
535
536 #ifdef BOYER_MOORE_CHECKS
537 /* we don't need to do these checks since memmem/strstr/etc do it already */
538 /* if the haystack is shorter than the needle then we can't possibly match */
539 if (haystacklen < needlelen)
540 return NULL;
541
542 /* instant match if the pattern buffer is 0-length */
543 if (needlelen == 0)
544 return (unsigned char *) haystack;
545 #endif /* BOYER_MOORE_CHECKS */
546
547 /* set a pointer at the end of each string */
548 ne_ptr = (unsigned char *) needle + needlelen - 1;
549 he_ptr = (unsigned char *) haystack + haystacklen - 1;
550
551 /* create our skip table */
552 for (i = 0; i < 256; i++)
553 skiptable[i] = needlelen;
554 for (nc_ptr = (unsigned char *) needle; nc_ptr < ne_ptr; nc_ptr++)
555 skiptable[bm_index (*nc_ptr, icase)] = (size_t) (ne_ptr - nc_ptr);
556
557 h_ptr = (unsigned char *) haystack;
558 while (haystacklen >= needlelen) {
559 hc_ptr = h_ptr + needlelen - 1; /* set the haystack compare pointer */
560 nc_ptr = ne_ptr; /* set the needle compare pointer */
561
562 /* work our way backwards till they don't match */
563 for (i = 0; nc_ptr > (unsigned char *) needle; nc_ptr--, hc_ptr--, i++)
564 if (!bm_equal (*nc_ptr, *hc_ptr, icase))
565 break;
566
567 if (!bm_equal (*nc_ptr, *hc_ptr, icase)) {
568 n = skiptable[bm_index (*hc_ptr, icase)];
569 if (n == needlelen && i)
570 if (bm_equal (*ne_ptr, ((unsigned char *) needle)[0], icase))
571 n--;
572 h_ptr += n;
573 haystacklen -= n;
574 } else
575 return (unsigned char *) h_ptr;
576 }
577
578 return NULL;
579 }
580
581 /*
582 * strcasestr:
583 * @haystack: string to search
584 * @needle: substring to search for
585 *
586 * Finds the first occurence of the substring @needle within the
587 * string @haystack ignoring case.
588 *
589 * Returns a pointer to the beginning of the substring match within
590 * @haystack, or NULL if the substring is not found.
591 **/
592 char *
593 strcasestr (const char *haystack, const char *needle)
594 {
595 register unsigned char *h, *n, *hc, *nc;
596 size_t needlelen;
597
598 needlelen = strlen (needle);
599
600 if (needlelen == 0) {
601 return (char *) haystack;
602 } else if (bm_optimal (0, needlelen)) {
603 return (char *) __boyer_moore ((const unsigned char *) haystack,
604 strlen (haystack),
605 (const unsigned char *) needle,
606 needlelen, 1);
607 }
608
609 h = (unsigned char *) haystack;
610 n = (unsigned char *) needle;
611
612 while (*(h + needlelen - 1)) {
613 if (lowercase (*h) == lowercase (*n)) {
614 for (hc = h + 1, nc = n + 1; *hc && *nc; hc++, nc++)
615 if (lowercase (*hc) != lowercase (*nc))
616 break;
617
618 if (!*nc)
619 return (char *) h;
620 }
621 h++;
622 }
623 return NULL;
624 }
625 #endif /* !HAVE_STRCASESTR */
626
513 /* vim: set expandtab cindent cinoptions=>2\:2(0: For Vim users... */ 627 /* vim: set expandtab cindent cinoptions=>2\:2(0: For Vim users... */