idn2\_to\_ascii\_lz(3) libidn2 idn2\_to\_ascii\_lz(3)

# [NAME](#NAME)

idn2\_to\_ascii\_lz - API function

# [SYNOPSIS](#SYNOPSIS)

**#include <idn2.h>**

**int idn2\_to\_ascii\_lz(const char * input, char \** output, int flags);**

# [ARGUMENTS](#ARGUMENTS)

[const char * input](#const)

zero terminated input UTF-8 string.

[char \** output](#char)

pointer to newly allocated output string.

[int flags](#int)

optional **idn2\_flags** to modify behaviour.

# [DESCRIPTION](#DESCRIPTION)

Convert a domain name in locale's encoding to ASCII string using the IDNA2008 rules. The domain name may contain several labels, separated by dots. The output buffer must be deallocated by the caller.

The default behavior of this function (when flags are zero) is to apply the IDNA2008 rules without the TR46 amendments. As the TR46 non-transitional processing is nowadays ubiquitous, when unsure, it is recommended to call this function with the **IDN2\_NONTRANSITIONAL** and the **IDN2\_NFC\_INPUT** flags for compatibility with other software.

# [RETURNS](#RETURNS)

**IDN2\_OK** on success, or error code. Same as described in **idn2\_lookup\_ul()** documentation.

# [SINCE](#SINCE)

2.0.0

# [REPORTING BUGS](#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)

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](#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/**

2.3.8 libidn2

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Document: idn2_to_ascii_lz(3) from libidn2 2.3.8-r12 (Chainguard OS)
Source: https://gitlab.com/libidn/libidn2