NAME

       uuidgen - create a new UUID value

SYNOPSIS

       uuidgen [options]

DESCRIPTION

       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 three types of UUIDs which uuidgen can generate: time-based UUIDs,  random-based
       UUIDs,  and  hash-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 first two UUID types by
       using the --random or --time options.

       The third type of UUID is  generated  with  the  --md5  or  --sha1  options,  followed  by
       --namespace  namespace and --name name.  The namespace may either be a well-known UUID, or
       else an alias to one of the well-known UUIDs defined in RFC  4122,  that  is  @dns,  @url,
       @oid,  or @x500.  The name is an arbitrary string value.  The generated UUID is the digest
       of the concatentation of the namespace UUID and the name value, hashed  with  the  MD5  or
       SHA1 algorithms.  It is, therefore, a predictable value which may be useful when UUIDs are
       being used as handles or nonces for more complex  values  or  values  which  shouldn't  be
       disclosed directly.  See the RFC for more information.

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.

       -m, --md5
              Use MD5 as the hash algorithm.

       -s, --sha1
              Use SHA1 as the hash algorith.

       -n, --namespace namespace
              Generate the hash with the namespace prefix. The namespace is UUID, or '@ns'  where
              "ns" is well-known predefined UUID addressed by namespace name (see above).

       -N, --name name
              Generate the hash of the name.

       -x, --hex
              Interpret name name as a hexidecimal string.

CONFORMING TO

       OSF DCE 1.1

EXAMPLES

       uuidgen --sha1 --namespace @dns --name "www.example.com"

AUTHOR

       uuidgen was written by Andreas Dilger for libuuid.

SEE ALSO

       libuuid(3), RFC 4122

AVAILABILITY

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