idn2_register_u8(3) libidn2 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 be-
fore 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_IN-
VALID_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/
libidn2 2.3.8 idn2_register_u8(3)
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