uuidgen
—
generate universally unique identifiers
uuidgen |
[-1s ] [-n
count] [-o
filename] |
The uuidgen
utility by default generates a single
universally unique identifier (UUID), also known as a globally unique
identifier (GUID). By default, uuidgen
generates a
single UUID and outputs it in the standard string representation to stdout.
The following options can be used to change the behavior of
uuidgen
:
-1
- This option only has effect if multiple identifiers are to be generated
and instructs
uuidgen
to not generate them in
batch, but one at a time.
-n
count
- This option controls the number of identifiers generated. By default,
multiple identifiers are generated in batch.
-o
filename
- Redirect output to filename instead of stdout.
-s
- Output UUIDs as initialized C structures, rather than in the standard
string format.
Batched generation yields a dense set of identifiers in such a way
that there is no identifier that is larger than the smallest identifier in
the set and smaller than the largest identifier in the set and that is not
already in the set.
When generating the identifiers one at a time, the identifiers
will be close to each other, but operating system latency and processing
time will be reflected in the distance between two successive
identifiers.
The uuidgen
utility exits 0 on success,
and >0 if an error occurs.
The uuidgen
command first appeared in
NetBSD 3.0.