uuidgen man page

uuidgen — create a new UUID value


uuidgen [options]


The uuidgen program creates (and prints) a new universally unique identifier (UUID) using the libuuid(3) library.  The new UUID can reasonably be considered unique among all UUIDs created on the local system, and among UUIDs created on other systems in the past and in the future.

There are two types of UUIDs which uuidgen can generate: time-based UUIDs and random-based UUIDs.  By default uuidgen will generate a random-based UUID if a high-quality random number generator is present.  Otherwise, it will choose a time-based UUID. It is possible to force the generation of one of these two UUID types by using the -r or -t options.


-r, --random

Generate a random-based UUID.  This method creates a UUID consisting mostly of random bits.  It requires that the operating system have a high quality random number generator, such as /dev/random.

-t, --time

Generate a time-based UUID.  This method creates a UUID based on the system clock plus the system's ethernet hardware address, if present.

-h, --help

Display help text and exit.

-V, --version

Display version information and exit.

Conforming to



uuidgen was written by Andreas Dilger for libuuid.

See Also



The uuidgen command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.

Referenced By

lcp_crtpolelt(8), swaplabel(8), uuidd(8), uuid_generate(3).

June 2011 util-linux User Commands