enca_analyser_alloc ()

EncaAnalyser        enca_analyser_alloc                 (const char *langname);

Allocates an analyser and initializes it for language language.

The analyser, once crerated, can be used only for language for which it was initialized. If you need to detect encodings of texts in more than one language, you must allocate an analyser for each one. Note however, an analyser may occupy a considerable amount of memory (a few hundreds of kB), so it's generally not a good idea to have several hundreds of them floating around.

langname is two-letter ISO 639:1989 language code. Locale names in form language_territory and ISO-639 English language names also may be accepted in the future. To be on the safe side, use only names returned by enca_get_languages().

enca_analyser_free ()

void                enca_analyser_free                  (EncaAnalyser analyser);

Frees memory used by EncaAnalyser analyser.

enca_analyse ()

EncaEncoding        enca_analyse                        (EncaAnalyser analyser,
                                                         unsigned char *buffer,
                                                         size_t size);

Analyses buffer and finds its encoding.

The buffer is checked for 8bit encodings of language for which analyser was initialized and for multibyte encodings, mostly independent on language (unless disabled with enca_set_multibyte()).

The contents of buffer may be (and probably will be) modified during the analyse. Use enca_analyse_const() instead if this discomforts you.

enca_analyse_const ()

EncaEncoding        enca_analyse_const                  (EncaAnalyser analyser,
                                                         unsigned char *buffer,
                                                         size_t size);

Analyses buffer and finds its encoding.

The buffer is checked for 8bit encodings of language for which analyser was initialized and for multibyte encodings, mostly independent on language (unless disabled with enca_set_multibyte()).

This function never modifies buffer (can be even used with string literal buffer) at the expense it's generally slower than enca_analyse().

enca_errno ()

int                 enca_errno                          (EncaAnalyser analyser);

Returns analyser error code.

The error code is not modified. However, any other analyser call i.e. call to a function taking analyser as parameter can change the error code.

enca_strerror ()

const char*         enca_strerror                       (EncaAnalyser analyser,
                                                         int errnum);

Returns string describing the error code.

The returned string must be considered constant and must NOT be freed. It is however gauranteed not to be modified on invalidated by subsequent calls to any libenca functions, including enca_strerror().

The analyser error code is not changed for a successful call, and it set to ENCA_EINVALUE upon error.

enca_double_utf8_check ()

int                 enca_double_utf8_check              (EncaAnalyser analyser,
                                                         unsigned char *buffer,
                                                         size_t size);

Checks buffer for double-UTF-8 encoding.

Double-UTF-8 encoding is the result of [errorneous] conversion of UTF-8 text to UTF-8 again, as if it was in some 8bit charset. This is quite hard to recover from.

The analayser mostly only determines what language will be assumed, the rest of this test is independent on the main guessing routines. When buffer doesn't containing UTF-8 text, the result is undefined (namely, false positives are possible).

Calling this function when language is `none' has currently no effect.

enca_double_utf8_get_candidates ()

int*                enca_double_utf8_get_candidates     (EncaAnalyser analyser);

Returns array of double-UTF-8 source charset candidates from the last check.

The returned array should be freed by caller then no longer needed. Its is the return value of the preceding enca_double_utf8_check() call.

When called before any double-UTF-8 test has been performed yet or after and unsuccessfull double-UTF-8 test, it returns NULL, but the result after an unsuccessfull check should be considered undefined.

enca_set_multibyte ()

void                enca_set_multibyte                  (EncaAnalyser analyser,
                                                         int multibyte);

Enables or disables multibyte encoding tests for analyser.

This option is enabled by default.

When multibyte encodings are disabled, only 8bit charsets are checked. Disabling them for language with no 8bit charsets leaves only one thing enca_analyse() could test: whether the sample is purely 7bit ASCII or not (the latter leading to analyser failure, of course).

Multibyte encoding detection is also affected by enca_set_termination_strictness().

enca_get_multibyte ()

int                 enca_get_multibyte                  (EncaAnalyser analyser);

Returns whether analyser can return multibyte encodings.

See enca_set_multibyte() for more detailed description of multibyte encoding checking.

Since 1.3.

enca_set_interpreted_surfaces ()

void                enca_set_interpreted_surfaces       (EncaAnalyser analyser,
                                                         int interpreted_surfaces);

Enables or disables interpeted surfaces tests for analyser.

This option is enabled by default.

To allow simple applications which care about charset only and don't want to wrestle with surfaces, neglecting surface information should not have serious consequences. While ignoring EOL type surface is feasible, and ignoring UCS byteorders may be acceptable in endian-homogenous environment; ignoring the fact file is Quoted-Printable encoded can have disasterous consequences. By disabling this option you can disable surfaces requiring fundamental reinterpretation of the content, namely ENCA_SURFACE_QP and ENCA_SURFACE_EOL_BIN (thus probably making enca_analyse() to fail on such samples).

enca_get_interpreted_surfaces ()

int                 enca_get_interpreted_surfaces       (EncaAnalyser analyser);

Returns whether analyser allows interpreted surfaces.

See enca_set_interpreted_surfaces() for more detailed description of interpreted surfaces.

Since 1.3.

enca_set_ambiguity ()

void                enca_set_ambiguity                  (EncaAnalyser analyser,
                                                         int ambiguity);

Enables or disables ambiguous mode for analyser.

This option is disabled by default.

In ambiguous mode some result is returned even when the charset cannot be determined uniquely, provided that sample contains only characters which have the same meaning in all charsets under consideration.

enca_get_ambiguity ()

int                 enca_get_ambiguity                  (EncaAnalyser analyser);

Returns whether analyser can return ambiguous results.

See enca_set_ambiguity() for more detailed description of ambiguous results.

Since 1.3.

enca_set_filtering ()

void                enca_set_filtering                  (EncaAnalyser analyser,
                                                         int filtering);

Enables or disables filters for analyser.

This option is enabled by default.

Various filters are used to filter out block of binary noise and box-drawing characters that could otherwise confuse enca. In cases this is unwanted, you can disable them by setting this option to zero.

enca_get_filtering ()

int                 enca_get_filtering                  (EncaAnalyser analyser);

Returns whether analyser has filtering enabled.

See enca_set_filtering() for more detailed description of filtering.

Since 1.3.

enca_set_garbage_test ()

void                enca_set_garbage_test               (EncaAnalyser analyser,
                                                         int garabage_test);

Enables or disables garbage test for analyser.

This option is enabled by default.

To prevent white noise (and almost-white noise) from being accidentally detected as some charset, a garbage test is used. In cases this is unwanted, you can disable is by setting this option to zero.

enca_get_garbage_test ()

int                 enca_get_garbage_test               (EncaAnalyser analyser);

Returns whether analyser has garbage test enabled.

See enca_set_garbage_test() for more detailed description of garbage test.

Since 1.3.

enca_set_termination_strictness ()

void                enca_set_termination_strictness     (EncaAnalyser analyser,
                                                         int termination_strictness);

Enables or disables requiring multibyte sequences to be terminated correctly at the end of sample.

This option is enabled by default.

The sample given to enca_analyse() generally may not be a complete text (e.g. for efficiency reasons). As a result, it may end in the middle of a multibyte sequence. In this case, you should disable this option to prevent rejecting some charset just because the sample don't terminate correctly. On the other hand, when given sample contains whole text, you should always enable this option to assure correctness of the result.

Note this option does NOT affect fixed character size encodings, like UCS-2 and UCS-4; sample is never assumed to contain UCS-2 text when its size is not even (and similarly for UCS-4).

enca_get_termination_strictness ()

int                 enca_get_termination_strictness     (EncaAnalyser analyser);

Returns whether analyser requires strict termination.

See enca_set_termination_strictness() for more detailed description of termination strictness.

Since 1.3.

enca_set_significant ()

int                 enca_set_significant                (EncaAnalyser analyser,
                                                         size_t significant);

Sets the minimal number of required significant characters.

The default value of this option is 10.

enca_analyse() refuses to make a decision unles at least this number of significant characters is found in sample. You may want to lower this number for very short texts.

enca_get_significant ()

size_t              enca_get_significant                (EncaAnalyser analyser);

Returns the minimum number of significant characters required by analyser.

See enca_set_significant() for more detailed description of required significant characters.

Since 1.3.

enca_set_threshold ()

int                 enca_set_threshold                  (EncaAnalyser analyser,
                                                         double threshold);

Sets the minimal ratio between the most probable and the second most probable charsets.

The default value of this option is 1.4142.

enca_analyse() consideres the result known only when there's a clear gap between the most probable and the second most probable charset proababilities. Lower threshold values mean larger probability of a mistake and smaller probability of not recognizing a charset; higher threshold values the contrary. Threshold value of 2 is almost infinity.

enca_get_threshold ()

double              enca_get_threshold                  (EncaAnalyser analyser);

Returns the threshold value used by analyser.

See enca_set_threshold() for more detailed threshold description.

Since 1.3.