stringprep\_utf8\_to\_ucs4(3) libidn stringprep\_utf8\_to\_ucs4(3)

# [NAME](#NAME)

stringprep\_utf8\_to\_ucs4 - API function

# [SYNOPSIS](#SYNOPSIS)

**#include <stringprep.h>**

**uint32\_t * stringprep\_utf8\_to\_ucs4(const char * str, ssize\_t len, size\_t * items\_written);**

# [ARGUMENTS](#ARGUMENTS)

[const char * str](#const)

a UTF-8 encoded string

[ssize\_t len](#ssize_t)

the maximum length of *str* to use. If *len* < 0, then the string is nul-terminated.

[size\_t * items\_written](#size_t)

location to store the number of characters in the result, or **NULL**.

# [DESCRIPTION](#DESCRIPTION)

Convert a string from UTF-8 to a 32-bit fixed width representation as UCS-4. The function now performs error checking to verify that the input is valid UTF-8 (before it was documented to not do error checking).

Return value: a pointer to a newly allocated UCS-4 string. This value must be deallocated by the caller.

# [REPORTING BUGS](#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)

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](#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/**

1.44 libidn

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Document: stringprep_utf8_to_ucs4(3) from libidn 1.44-r6 (Chainguard OS)
Source: https://gitlab.com/libidn/libidn