punycode_encode(3)

NAME
punycode_encode - API function

SYNOPSIS
#include <punycode.h>

int punycode_encode(size_t input_length, const punycode_uint [] input, const unsigned char [] case_flags, size_t * output_length, char [] output);

ARGUMENTS

size_t input_length
    The number of code points in the input array and the number of flags in the case_flags array.

const punycode_uint [] input
    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.

const unsigned char [] case_flags
    A NULL pointer or an array of boolean values parallel to the input array. 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. If case_flags is a NULL pointer then ASCII letters are left as they are, and other code points are treated as unflagged.

size_t * output_length
    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.

char [] output
    An array of ASCII code points. It is *not* null-terminated; it will contain zeros if and only if the input contains zeros. (Of course the caller can leave room for a terminator and add one if needed.)

DESCRIPTION
Converts a sequence of code points (presumed to be Unicode code points) to Punycode. Return value: The return value can be any of the Punycode_status values defined above except PUNYCODE_BAD_INPUT. If not PUNYCODE_SUCCESS, then output_size and output might contain garbage.

DESCRIPTION
Converts a sequence of code points (presumed to be Unicode code points) to Punycode. Return value: The return value can be any of the Punycode_status values defined above except PUNYCODE_BAD_INPUT. If not PUNYCODE_SUCCESS, then output_size and output might contain garbage.

REPORTING BUGS
Report bugs to <help-libidn@gnu.org>.
General guidelines for reporting bugs: https://www.gnu.org/gethelp/
GNU Libidn home page: https://www.gnu.org/software/libidn/

COPYRIGHT
Copyright © 2002-2026 Simon Josefsson.
Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.

SEE ALSO
The full documentation for libidn is maintained as a Texinfo manual. If the info and libidn programs are properly installed at your site, the command

    info libidn

should give you access to the complete manual. As an alternative you may obtain the manual from:

    https://www.gnu.org/software/libidn/manual/