idna_to_unicode_44i man page

idna_to_unicode_44i — API function


#include <idna.h>

int idna_to_unicode_44i(const uint32_t * in, size_t inlen, uint32_t * out, size_t * outlen, int flags);


const uint32_t * in

input array with unicode code points.

size_t inlen

length of input array with unicode code points.

uint32_t * out

output array with unicode code points.

size_t * outlen

on input, maximum size of output array with unicode code points, on exit, actual size of output array with unicode code points.

int flags



The ToUnicode operation takes a sequence of Unicode code points that make up one domain label and returns a sequence of Unicode code points. If the input sequence is a label in ACE form, then the result is an equivalent internationalized label that is not in ACE form, otherwise the original sequence is returned unaltered.

ToUnicode never fails. If any step fails, then the original input sequence is returned immediately in that step.

The Punycode decoder can never output more code points than it inputs, but Nameprep can, and therefore ToUnicode can.  Note that the number of octets needed to represent a sequence of code points depends on the particular character encoding used.

The inputs to ToUnicode are a sequence of code points, the AllowUnassigned flag, and the UseSTD3ASCIIRules flag. The output of ToUnicode is always a sequence of Unicode code points.

Return value: Returns Idna_rc error condition, but it must only be used for debugging purposes.  The output buffer is always guaranteed to contain the correct data according to the specification (sans malloc induced errors).  NB!  This means that you normally ignore the return code from this function, as checking it means breaking the standard.

Reporting Bugs

Report bugs to <>.
General guidelines for reporting bugs:
GNU Libidn home page:

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:


1.33 libidn