uuidgen
Generate new UUID values
TLDR
Generate a random UUID (v4)
$ uuidgen -r
Generate a time-based UUID (v1)$ uuidgen -t
Generate a time-based sortable UUID (v7)$ uuidgen -7
Generate a SHA1-based UUID (v5) from a namespace and name$ uuidgen -s -n @dns -N [example.com]
Generate a MD5-based UUID (v3) from a namespace and name$ uuidgen -m -n @url -N [https://example.com]
Generate multiple time-based UUIDs at once$ uuidgen -t -C [5]
SYNOPSIS
uuidgen [options]
DESCRIPTION
uuidgen creates a new universally unique identifier (UUID). By default it generates a random UUID (version 4). Time-based (v1) UUIDs include timestamp and MAC address. Name-based UUIDs (v3/v5) are deterministic, generating the same UUID for the same namespace and name combination.UUIDs are 128-bit identifiers commonly used for unique identification in databases, distributed systems, and file systems.
PARAMETERS
-r, --random
Generate random UUID (version 4)-t, --time
Generate time-based UUID (version 1)-7, --time-v7
Generate time-based UUID (version 7), lexicographically sortable by timestamp-s, --sha1
Generate SHA1-based UUID (version 5)-m, --md5
Generate MD5-based UUID (version 3)-n, --namespace _ns_
Namespace for name-based UUIDs (@dns, @url, @oid, @x500)-N, --name _name_
Name for name-based UUIDs-x, --hex
Interpret name as a hexadecimal string-C, --count _num_
Generate multiple UUIDs-h, --help
Display help text and exit-V, --version
Print version and exit
UUID VERSIONS
v1: Time and MAC address basedv3: MD5 hash of namespace and namev4: Randomv5: SHA1 hash of namespace and namev7: Time-based, lexicographically sortable (RFC 9562)
CAVEATS
Time-based UUIDs expose the MAC address of the generating machine. For privacy, prefer random UUIDs. Part of the util-linux package.
SEE ALSO
uuid(1)
