UUIDGEN(1) UUIDGEN(1) (NAME) uuidgen - (UUID) (SYNOPSIS) uuidgen [] (DESCRIPTION) uuidgen libuuid(3) (UUID) ( ) . UUID UUID UUID . UUID uuidgen : UUID (time-based) UUID (random-based) UUID (hash-based). uuidgen UUID . UUID . --random --time UUID . UUID --md5 --sha1 --namespace namespace --name name . namespace UUID UUID RFC 4122 @dns @url @oid @x500 . name . UUID (digest) UUID MD5 SHA1 . UUID (handles) (nonces) . RFC . (OPTIONS) -r --random UUID . UUID . /dev/random. -t --time UUID . UUID ( ) . -m --md5 MD5 . -s --sha1 SHA1 . -6 --time-v6 UUID . UUID (lexicographically) . -7 --time-v7 UUID . UUID . -n --namespace namespace namespace. namespace UUID '@ns' "ns" UUID ( ). -N --name name name. -C --count num UUID libuuid UUID . UUID . -x --hex name . -h --help . -V --version . (CONFORMING TO) OSF DCE 1.1 (EXAMPLES) uuidgen --sha1 --namespace @dns --name "www.example.com" (AUTHORS) uuidgen Andreas Dilger libuuid(3) . (SEE ALSO) uuidparse(1) libuuid(3) RFC 4122 RFC XXXX (REPORTING BUGS) . (AVAILABILITY) uuidgen util-linux . . util-linux 2.42.3 2026-09-02 UUIDGEN(1)