1idn2_lookup_u8(3)                   libidn2                  idn2_lookup_u8(3)
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NAME

6       idn2_lookup_u8 - API function
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SYNOPSIS

9       #include <idn2.h>
10
11       int  idn2_lookup_u8(const  uint8_t  *  src,  uint8_t ** lookupname, int
12       flags);
13

ARGUMENTS

15       const uint8_t * src
16                   input zero-terminated UTF-8 string in Unicode  NFC  normal‐
17                   ized form.
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19       uint8_t ** lookupname
20                   newly allocated output variable with name to lookup in DNS.
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22       int flags   optional idn2_flags to modify behaviour.
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DESCRIPTION

25       Perform  IDNA2008 lookup string conversion on domain name  src , as de‐
26       scribed in section 5 of RFC 5891.  Note that the input string  must  be
27       encoded in UTF-8 and be in Unicode NFC form.
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29       Pass  IDN2_NFC_INPUT in  flags to convert input to NFC form before fur‐
30       ther processing.  IDN2_TRANSITIONAL and IDN2_NONTRANSITIONAL do already
31       imply IDN2_NFC_INPUT.
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33       Pass  IDN2_ALABEL_ROUNDTRIP  in  flags to convert any input A-labels to
34       U-labels and perform additional testing. This is default since  version
35       2.2.  To switch this behavior off, pass IDN2_NO_ALABEL_ROUNDTRIP
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37       Pass  IDN2_TRANSITIONAL to enable Unicode TR46 transitional processing,
38       and IDN2_NONTRANSITIONAL to enable Unicode TR46  non-transitional  pro‐
39       cessing.
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41       Multiple flags may be specified by binary or:ing them together.
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43       After  version  2.0.3:  IDN2_USE_STD3_ASCII_RULES  disabled by default.
44       Previously we were eliminating non-STD3 characters from domain  strings
45       such  as  _443._tcp.example.com,  or IPs 1.2.3.4/24 provided to libidn2
46       functions. That was an unexpected regression for applications switching
47       from  libidn  and  thus  it  is  no  longer  applied  by  default.  Use
48       IDN2_USE_STD3_ASCII_RULES to enable that behavior again.
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50       After version 0.11:  lookupname may be NULL  to  test  lookup  of   src
51       without allocating memory.
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RETURNS

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

59       0.1
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SEE ALSO

62       The  full  documentation for libidn2 is maintained as a Texinfo manual.
63       If the info and libidn2 programs are properly installed at  your  site,
64       the command
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66              info libidn2
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68       should  give  you access to the complete manual.  As an alternative you
69       may obtain the manual from:
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71              https://www.gnu.org/software/libidn/libidn2/manual/
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73libidn2                          2.3.1.48-1925               idn2_lookup_u8(3)