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bup-random(1)		    General Commands Manual		 bup-random(1)

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  in-
       tentional:  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 microbench-
       marks.

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	 giga-
	      bytes, 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>

Bup 0.32			  2021-01-09			 bup-random(1)

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