NAME

       idn2_lookup_u8 - API function

SYNOPSIS

       #include <idn2.h>

       int idn2_lookup_u8(const uint8_t * src, uint8_t ** lookupname, int flags);

ARGUMENTS

       const uint8_t * src
                   input zero-terminated UTF-8 string in Unicode NFC normalized form.

       uint8_t ** lookupname
                   newly allocated output variable with name to lookup in DNS.

       int flags   optional idn2_flags to modify behaviour.

DESCRIPTION

       Perform  IDNA2008 lookup string conversion on domain name  src , as described in section 5
       of RFC 5891.  Note that the input string must be encoded in UTF-8 and be  in  Unicode  NFC
       form.

       Pass  IDN2_NFC_INPUT  in   flags  to  convert input to NFC form before further processing.
       IDN2_TRANSITIONAL and IDN2_NONTRANSITIONAL do already imply IDN2_NFC_INPUT.

       Pass IDN2_ALABEL_ROUNDTRIP in  flags to convert any input A-labels to U-labels and perform
       additional  testing. This is default since version 2.2.  To switch this behavior off, pass
       IDN2_NO_ALABEL_ROUNDTRIP

       Pass   IDN2_TRANSITIONAL   to   enable   Unicode   TR46   transitional   processing,   and
       IDN2_NONTRANSITIONAL to enable Unicode TR46 non-transitional processing.

       Multiple flags may be specified by binary or:ing them together.

       After  version  2.0.3:  IDN2_USE_STD3_ASCII_RULES disabled by default.  Previously we were
       eliminating non-STD3 characters from domain strings such as _443._tcp.example.com, or  IPs
       1.2.3.4/24   provided  to  libidn2  functions.  That  was  an  unexpected  regression  for
       applications switching from libidn and thus it is  no  longer  applied  by  default.   Use
       IDN2_USE_STD3_ASCII_RULES to enable that behavior again.

       After  version  0.11:   lookupname  may  be NULL to test lookup of  src without allocating
       memory.

RETURNS

       On successful conversion IDN2_OK is returned, if the output domain or any label would have
       been too long IDN2_TOO_BIG_DOMAIN or IDN2_TOO_BIG_LABEL is returned, or another error code
       is returned.

SINCE

       0.1

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 © 2002-2022 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/