NAME

       bup-random - generate a stream of random output

SYNOPSIS

       bup random [-S seed][-fv] <numbytes>

DESCRIPTION

       bup random  produces  a stream of pseudorandom output bytes to stdout.  Note: the bytes are not generated
       using a cryptographic algorithm and should never be used for security.

       Note that the stream of random bytes will be identical every time bup random is run, unless you provide a
       different  seed  value.  This is intentional: the purpose of this program is to be able to run repeatable
       tests on large amounts of data, so we want identical data every time.

       bup random generates about 240 megabytes per second on a modern  test  system  (Intel  Core2),  which  is
       faster  than  you  could  achieve  by reading data from most disks.  Thus, it can be helpful when running
       microbenchmarks.

OPTIONS

       <numbytes>
              the number of bytes of data to generate.  Can be used with the suffices k, M,  or  G  to  indicate
              kilobytes, megabytes, or gigabytes, respectively.

       -S, --seed=seed
              use  the  given value to seed the pseudorandom number generator.  The generated output stream will
              be identical for every stream seeded with the same value.  The default seed is 1.  A seed value of
              0 is equivalent to 1.

       -f, --force
              generate output even if stdout is a tty.  (Generating random data to a tty is generally considered
              ill-advised, but you can do if you really want.)

       -v, --verbose
              print a progress message showing the number of bytes that has been output so far.

EXAMPLES

              $ bup random 1k | sha1sum
              2108c55d0a2687c8dacf9192677c58437a55db71  -

              $ bup random -S1 1k | sha1sum
              2108c55d0a2687c8dacf9192677c58437a55db71  -

              $ bup random -S2 1k | sha1sum
              f71acb90e135d98dad7efc136e8d2cc30573e71a  -

              $ time bup random 1G >/dev/null
              Random: 1024 Mbytes, done.

              real   0m4.261s
              user   0m4.048s
              sys    0m0.172s

              $ bup random 1G | bup split -t --bench
              Random: 1024 Mbytes, done.
              bup: 1048576.00kbytes in 18.59 secs = 56417.78 kbytes/sec
              1092599b9c7b2909652ef1e6edac0796bfbfc573

BUP

       Part of the bup(1) suite.

AUTHORS

       Avery Pennarun <apenwarr@gmail.com>.