UUID\_IS\_NULL(3) Programmers Manual UUID\_IS\_NULL(3)

# [NAME](#NAME)

uuid\_is\_null - compare the value of the UUID to the NULL value

# [SYNOPSIS](#SYNOPSIS)

**#include <uuid.h>**

**int uuid\_is\_null(const uuid\_t uu);**

# [DESCRIPTION](#DESCRIPTION)

The **uuid\_is\_null**() function compares the value of the supplied UUID variable *uu* to the NULL value. If the value is equal to the NULL UUID, 1 is returned, otherwise 0 is returned.

# [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\_parse**(3)](/man/os/util-linux/uuid_parse.3), [**uuid\_unparse**(3)](/man/os/util-linux/uuid_unparse.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/>.

2026-10-30 util-linux 2.42.4

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Document: uuid_is_null(3) from util-linux 2.42.4-r2 (Chainguard OS)