---
name: "idn2_to_ascii_8z"
section: "3"
platform: "linux"
package: "libidn2"
version: "2.3.8-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/idn2_to_ascii_8z"
---

# idn2\_to\_ascii\_8z(3)

API function

## NAME

idn2\_to\_ascii\_8z - API function

## SYNOPSIS

**#include \<idn2.h\>**

**int idn2\_to\_ascii\_8z(const char \*** *input***, char \*\*** *output***, int** *flags***);**

## ARGUMENTS

- const char \* input

  zero terminated input UTF-8 string.

- char \*\* output

  pointer to newly allocated output string.

- int flags

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

## DESCRIPTION

Convert UTF-8 domain name 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.

Return value: Returns **IDN2\_OK** on success, or error code.

## SINCE

2\.0.0

## 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/**