idn2_register_u8(3)

NAME
idn2_register_u8 - API function

SYNOPSIS
#include <idn2.h>

int idn2_register_u8(const uint8_t * ulabel, const uint8_t * alabel, uint8_t ** insertname, int flags);

ARGUMENTS

const uint8_t * ulabel
    input zero-terminated UTF-8 and Unicode NFC string, or NULL.

const uint8_t * alabel
    input zero-terminated ACE encoded string (xn--), or NULL.

uint8_t ** insertname
    newly allocated output variable with name to register in DNS.

int flags
    optional idn2_flags to modify behaviour.

DESCRIPTION
Perform IDNA2008 register string conversion on domain label ulabel and alabel , as described in section 4 of RFC 5891. Note that the input ulabel must be encoded in UTF-8 and be in Unicode NFC form.

Pass IDN2_NFC_INPUT in flags to convert input ulabel to NFC form before further processing.

It is recommended to supply both ulabel and alabel for better error checking, but supplying just one of them will work. Passing in only alabel is better than only ulabel . See RFC 5891 section 4 for more information.

After version 0.11: insertname may be NULL to test conversion of src without allocating memory.

RETURNS
On successful conversion IDN2_OK is returned, when the given ulabel and alabel does not match each other IDN2_UALABEL_MISMATCH is returned, when either of the input labels are too long IDN2_TOO_BIG_LABEL is returned, when alabel does does not appear to be a proper A-label IDN2_INVALID_ALABEL is returned, or another error code is returned.

REPORTING BUGS
Report bugs to <help-libidn@gnu.org>.
General guidelines for reporting bugs: https://www.gnu.org/gethelp/
Libidn2 home page: https://www.gnu.org/software/libidn2/

COPYRIGHT
Copyright © 2002-2025 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 libidn2 is maintained as a Texinfo manual. If the info and libidn2 programs are properly installed at your site, the command

    info libidn2

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

    https://www.gnu.org/software/libidn/libidn2/manual/