---
name: "tld_check_4"
section: "3"
platform: "linux"
package: "libidn"
version: "1.44-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/tld_check_4"
---

# tld\_check\_4(3)

API function

## NAME

tld\_check\_4 - API function

## SYNOPSIS

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

**int tld\_check\_4(const uint32\_t \*** *in***, size\_t** *inlen***, size\_t \*** *errpos***, const Tld\_table \*\*** *overrides***);**

## ARGUMENTS

- const uint32\_t \* in

  Array of unicode code points to process. Does not need to be zero terminated.

- size\_t inlen

  Number of unicode code points.

- size\_t \* errpos

  Position of offending character is returned here.

- const Tld\_table \*\* overrides

  A **Tld\_table** array of additional domain restriction structures that complement and supersede the built-in information.

## DESCRIPTION

Test each of the code points in  *in* for whether or not they are allowed by the information in  *overrides* or by the built-in TLD restriction data. When data for the same TLD is available both internally and in  *overrides* , the information in  *overrides* takes precedence. If several entries for a specific TLD are found, the first one is used.  If  *overrides* is **NULL**, only the built-in information is used.  The position of the first offending character is returned in  *errpos* .

Return value: Returns the **Tld\_rc** value **TLD\_SUCCESS** if all code points are valid or when  *tld* is null, **TLD\_INVALID** if a character is not allowed, or additional error codes on general failure conditions.

## REPORTING BUGS

Report bugs to \<help-libidn@gnu.org\>.\
 General guidelines for reporting bugs: https://www.gnu.org/gethelp/\
 GNU Libidn home page: https://www.gnu.org/software/libidn/

## COPYRIGHT

Copyright © 2002-2026 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 **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:

-

  **https://www.gnu.org/software/libidn/manual/**