|  |  |  | GNU Libidn API Reference Manual |  | 
|---|---|---|---|---|
enum Punycode_status; const char* punycode_strerror (Punycode_status rc); typedef punycode_uint; int punycode_encode (size_t input_length, const punycode_uint input[], unsigned char case_flags[], size_t *output_length, char output[]); int punycode_decode (size_t input_length, const char input[], size_t *output_length, punycode_uint output[], unsigned char case_flags[]);
  typedef enum
  {
    PUNYCODE_SUCCESS = punycode_success,
    PUNYCODE_BAD_INPUT = punycode_bad_input,
    PUNYCODE_BIG_OUTPUT = punycode_big_output,
    PUNYCODE_OVERFLOW = punycode_overflow
  } Punycode_status;
Enumerated return codes of punycode_encode() and punycode_decode().
The value 0 is guaranteed to always correspond to success.
| Successful operation. This value is guaranteed to always be zero, the remaining ones are only guaranteed to hold non-zero values, for logical comparison purposes. | |
| Input is invalid. | |
| Output would exceed the space provided. | |
| Input needs wider integers to process. | 
const char* punycode_strerror (Punycode_status rc);
Convert a return code integer to a text string. This string can be used to output a diagnostic message to the user.
PUNYCODE_SUCCESS: Successful operation. This value is guaranteed to always be zero, the remaining ones are only guaranteed to hold non-zero values, for logical comparison purposes. PUNYCODE_BAD_INPUT: Input is invalid. PUNYCODE_BIG_OUTPUT: Output would exceed the space provided. PUNYCODE_OVERFLOW: Input needs wider integers to process.
| 
 | an Punycode_status return code. | 
| Returns : | Returns a pointer to a statically allocated string
containing a description of the error with the return code rc. | 
typedef uint32_t punycode_uint;
Unicode code point data type, this is always a 32 bit unsigned integer.
int                 punycode_encode                     (size_t input_length,
                                                         const punycode_uint input[],
                                                         unsigned char case_flags[],
                                                         size_t *output_length,
                                                         char output[]);
Converts a sequence of code points (presumed to be Unicode code points) to Punycode.
| 
 | The number of code points in the inputarray and
  the number of flags in thecase_flagsarray. | 
| 
 | An array of code points. They are presumed to be Unicode code points, but that is not strictly REQUIRED. The array contains code points, not code units. UTF-16 uses code units D800 through DFFF to refer to code points 10000..10FFFF. The code points D800..DFFF do not occur in any valid Unicode string. The code points that can occur in Unicode strings (0..D7FF and E000..10FFFF) are also called Unicode scalar values. | 
| 
 | A NULLpointer or an array of boolean values parallel
  to theinputarray.  Nonzero (true, flagged) suggests that the
  corresponding Unicode character be forced to uppercase after
  being decoded (if possible), and zero (false, unflagged) suggests
  that it be forced to lowercase (if possible).  ASCII code points
  (0..7F) are encoded literally, except that ASCII letters are
  forced to uppercase or lowercase according to the corresponding
  case flags.  Ifcase_flagsis aNULLpointer then ASCII letters
  are left as they are, and other code points are treated as
  unflagged. | 
| 
 | The caller passes in the maximum number of ASCII code points that it can receive. On successful return it will contain the number of ASCII code points actually output. | 
| 
 | An array of ASCII code points.  It is *not*
  null-terminated; it will contain zeros if and only if the inputcontains zeros.  (Of course the caller can leave room for a
  terminator and add one if needed.) | 
| Returns : | The return value can be any of the Punycode_status
  values defined above except PUNYCODE_BAD_INPUT.  If notPUNYCODE_SUCCESS, thenoutput_sizeandoutputmight contain
  garbage. | 
int                 punycode_decode                     (size_t input_length,
                                                         const char input[],
                                                         size_t *output_length,
                                                         punycode_uint output[],
                                                         unsigned char case_flags[]);
Converts Punycode to a sequence of code points (presumed to be Unicode code points).
| 
 | The number of ASCII code points in the inputarray. | 
| 
 | An array of ASCII code points (0..7F). | 
| 
 | The caller passes in the maximum number of code
  points that it can receive into the outputarray (which is also
  the maximum number of flags that it can receive into thecase_flagsarray, ifcase_flagsis not aNULLpointer).  On
  successful return it will contain the number of code points
  actually output (which is also the number of flags actually
  output, if case_flags is not a null pointer).  The decoder will
  never need to output more code points than the number of ASCII
  code points in the input, because of the way the encoding is
  defined.  The number of code points output cannot exceed the
  maximum possible value of a punycode_uint, even if the suppliedoutput_lengthis greater than that. | 
| 
 | An array of code points like the input argument of punycode_encode()(see above). | 
| 
 | A NULLpointer (if the flags are not needed by the
  caller) or an array of boolean values parallel to theoutputarray.  Nonzero (true, flagged) suggests that the corresponding
  Unicode character be forced to uppercase by the caller (if
  possible), and zero (false, unflagged) suggests that it be forced
  to lowercase (if possible).  ASCII code points (0..7F) are output
  already in the proper case, but their flags will be set
  appropriately so that applying the flags would be harmless. | 
| Returns : | The return value can be any of the Punycode_status
  values defined above.  If not PUNYCODE_SUCCESS, thenoutput_length,output, andcase_flagsmight contain garbage. |