* This class, based on Unicode Technical Report #36 and * Unicode Technical Standard #39, has two main functions: * *
* Although originally designed as a method for flagging suspicious identifier strings such as URLs,
* USpoofChecker has a number of other practical use cases, such as preventing attempts to evade bad-word
* content filters.
*
*
* The functions of this class are exposed as C API, with a handful of syntactical conveniences for C++. * *
* The following example shows how to use USpoofChecker to check for confusability between two strings:
*
* \code{.c}
* UErrorCode status = U_ZERO_ERROR;
* UChar* str1 = (UChar*) u"Harvest";
* UChar* str2 = (UChar*) u"\u0397arvest"; // with U+0397 GREEK CAPITAL LETTER ETA
*
* USpoofChecker* sc = uspoof_open(&status);
* uspoof_setChecks(sc, USPOOF_CONFUSABLE, &status);
*
* int32_t bitmask = uspoof_areConfusable(sc, str1, -1, str2, -1, &status);
* UBool result = bitmask != 0;
* // areConfusable: 1 (status: U_ZERO_ERROR)
* printf("areConfusable: %d (status: %s)\n", result, u_errorName(status));
* uspoof_close(sc);
* \endcode
*
*
* The call to {@link uspoof_open} creates a USpoofChecker object; the call to {@link uspoof_setChecks}
* enables confusable checking and disables all other checks; the call to {@link uspoof_areConfusable} performs the
* confusability test; and the following line extracts the result out of the return value. For best performance,
* the instance should be created once (e.g., upon application startup), and the efficient
* {@link uspoof_areConfusable} method can be used at runtime.
*
*
* The type {@link LocalUSpoofCheckerPointer} is exposed for C++ programmers. It will automatically call * {@link uspoof_close} when the object goes out of scope: * * \code{.cpp} * UErrorCode status = U_ZERO_ERROR; * LocalUSpoofCheckerPointer sc(uspoof_open(&status)); * uspoof_setChecks(sc.getAlias(), USPOOF_CONFUSABLE, &status); * // ... * \endcode * * UTS 39 defines two strings to be confusable if they map to the same skeleton string. A skeleton can * be thought of as a "hash code". {@link uspoof_getSkeleton} computes the skeleton for a particular string, so * the following snippet is equivalent to the example above: * * \code{.c} * UErrorCode status = U_ZERO_ERROR; * UChar* str1 = (UChar*) u"Harvest"; * UChar* str2 = (UChar*) u"\u0397arvest"; // with U+0397 GREEK CAPITAL LETTER ETA * * USpoofChecker* sc = uspoof_open(&status); * uspoof_s