UUID\_UNPARSE(3) Programmers Manual UUID\_UNPARSE(3)

# [NAME](#NAME)

uuid\_unparse - convert a UUID from binary representation to a string

# [SYNOPSIS](#SYNOPSIS)

**#include <uuid.h>**

**void uuid\_unparse(const uuid\_t uu, char \*out);**  
**void uuid\_unparse\_upper(const uuid\_t uu, char \*out);**  
**void uuid\_unparse\_lower(const uuid\_t uu, char \*out);**

# [DESCRIPTION](#DESCRIPTION)

The **uuid\_unparse**() function converts the supplied UUID *uu* from the binary representation into a 36-byte string (plus trailing '\\0') of the form 1b4e28ba-2fa1-11d2-883f-0016d3cca427 and stores this value in the character string pointed to by *out*. The case of the hex digits returned by **uuid\_unparse**() may be upper or lower case, and is dependent on the system-dependent local default.

If the case of the hex digits is important then the functions **uuid\_unparse\_upper**() and **uuid\_unparse\_lower**() may be used.

# [CONFORMING TO](#CONFORMING_TO)

This library unparses UUIDs compatible with OSF DCE 1.1.

# [AUTHORS](#AUTHORS)

Theodore Y. Ts’o

# [SEE ALSO](#SEE_ALSO)

[**uuid**(3)](/man/os/util-linux/uuid.3), [**uuid\_clear**(3)](/man/os/util-linux/uuid_clear.3), [**uuid\_compare**(3)](/man/os/util-linux/uuid_compare.3), [**uuid\_copy**(3)](/man/os/util-linux/uuid_copy.3), [**uuid\_generate**(3)](/man/os/util-linux/uuid_generate.3), [**uuid\_time**(3)](/man/os/util-linux/uuid_time.3), [**uuid\_is\_null**(3)](/man/os/util-linux/uuid_is_null.3), [**uuid\_parse**(3)](/man/os/util-linux/uuid_parse.3)

# [REPORTING BUGS](#REPORTING_BUGS)

For bug reports, use the *issue tracker* <https://github.com/util-linux/util-linux/issues>.

# [AVAILABILITY](#AVAILABILITY)

The **libuuid** library is part of the util-linux package since version 2.15.1. It can be downloaded from *Linux Kernel Archive* <https://www.kernel.org/pub/linux/utils/util-linux/>.

2026-10-19 util-linux 2.42.4

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Document: uuid_unparse(3) from util-linux 2.42.4-r1 (Chainguard OS)