/* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive comparison from the C locale, regardless of the current locale. */ char * c_strcasestr (const char *haystack_start, const char *needle_start) { const char *haystack = haystack_start; const char *needle = needle_start; size_t needle_len; /* Length of NEEDLE. */ size_t haystack_len; /* Known minimum length of HAYSTACK. */ bool ok = true; /* True if NEEDLE is prefix of HAYSTACK. */ /* Determine length of NEEDLE, and in the process, make sure HAYSTACK is at least as long (no point processing all of a long NEEDLE if HAYSTACK is too short). */ while (*haystack && *needle) ok &= (c_tolower ((unsigned char) *haystack++) == c_tolower ((unsigned char) *needle++)); if (*needle) return NULL; if (ok) return (char *) haystack_start; needle_len = needle - needle_start; haystack = haystack_start + 1; haystack_len = needle_len - 1; /* Perform the search. Abstract memory is considered to be an array of 'unsigned char' values, not an array of 'char' values. See ISO C 99 section 6.2.6.1. */ if (needle_len < LONG_NEEDLE_THRESHOLD) return two_way_short_needle ((const unsigned char *) haystack, haystack_len, (const unsigned char *) needle_start, needle_len); return two_way_long_needle ((const unsigned char *) haystack, haystack_len, (const unsigned char *) needle_start, needle_len); }
/* Return the first occurrence of NEEDLE in HAYSTACK. Return HAYSTACK if NEEDLE is empty, otherwise NULL if NEEDLE is not found in HAYSTACK. */ char * STRSTR (const char *haystack_start, const char *needle_start) { const char *haystack = haystack_start; const char *needle = needle_start; size_t needle_len; /* Length of NEEDLE. */ size_t haystack_len; /* Known minimum length of HAYSTACK. */ bool ok = true; /* True if NEEDLE is prefix of HAYSTACK. */ #if 0 fprintf(stderr, "libc-arm-2012-03-fix strstr called\n"); #endif /* Determine length of NEEDLE, and in the process, make sure HAYSTACK is at least as long (no point processing all of a long NEEDLE if HAYSTACK is too short). */ while (*haystack && *needle) ok &= *haystack++ == *needle++; if (*needle) return NULL; if (ok) return (char *) haystack_start; /* Reduce the size of haystack using strchr, since it has a smaller linear coefficient than the Two-Way algorithm. */ needle_len = needle - needle_start; haystack = strchr (haystack_start + 1, *needle_start); if (!haystack || __builtin_expect (needle_len == 1, 0)) return (char *) haystack; needle -= needle_len; haystack_len = (haystack > haystack_start + needle_len ? 1 : needle_len + haystack_start - haystack); /* Perform the search. Abstract memory is considered to be an array of 'unsigned char' values, not an array of 'char' values. See ISO C 99 section 6.2.6.1. */ if (needle_len < LONG_NEEDLE_THRESHOLD) return two_way_short_needle ((const unsigned char *) haystack, haystack_len, (const unsigned char *) needle, needle_len); return two_way_long_needle ((const unsigned char *) haystack, haystack_len, (const unsigned char *) needle, needle_len); }
void * twoway_memmem (const void *haystack_start, size_t haystack_len, const void *needle_start, size_t needle_len) { /* Abstract memory is considered to be an array of 'unsigned char' values, not an array of 'char' values. See ISO C 99 section 6.2.6.1. */ const unsigned char *haystack = (const unsigned char *) haystack_start; const unsigned char *needle = (const unsigned char *) needle_start; if (needle_len == 0) /* The first occurrence of the empty string is deemed to occur at the beginning of the string. */ return (void *) haystack; /* Sanity check, otherwise the loop might search through the whole memory. */ if (__glibc_unlikely (haystack_len < needle_len)) return NULL; /* Use optimizations in memchr when possible, to reduce the search size of haystack using a linear algorithm with a smaller coefficient. However, avoid memchr for long needles, since we can often achieve sublinear performance. */ if (needle_len < LONG_NEEDLE_THRESHOLD) { haystack = memchr (haystack, *needle, haystack_len); if (!haystack || __builtin_expect (needle_len == 1, 0)) return (void *) haystack; haystack_len -= haystack - (const unsigned char *) haystack_start; if (haystack_len < needle_len) return NULL; /* Check whether we have a match. This improves performance since we avoid the initialization overhead of the two-way algorithm. */ if (memcmp (haystack, needle, needle_len) == 0) return (void *) haystack; return two_way_short_needle (haystack, haystack_len, needle, needle_len); } else return two_way_long_needle (haystack, haystack_len, needle, needle_len); }