Random number generator (device): Difference between revisions

=={{header|NetRexx}}==

{{Works with|Mac OS X}} and probably other UNIX systems that provide <tt>/dev/random</tt> or <tt>/dev/urandom</tt> random data source devices.<br />

<lang NetRexx>/* NetRexx */

options replace format comments java crossref savelog symbols binary

import java.math.BigInteger

randomDevNameFile = File

randomDevNameList = ['/dev/random', '/dev/urandom'] -- list of random data source devices

randomDevIStream = InputStream

do

loop dn = 0 to randomDevNameList.length - 1

randomDevNameFile = File(randomDevNameList[dn])

if randomDevNameFile.exists() then leave dn -- We're done! Use this device

randomDevNameFile = null -- ensure we don't use a non-existant device

end dn

if randomDevNameFile == null then signal FileNotFoundException('Cannot locate a random data source device on this system')

-- read 8 bytes from the random data source device, convert it into a BigInteger then display the result

randomBytes = byte[8]

randomDevIStream = BufferedInputStream(FileInputStream(randomDevNameFile))

randomDevIStream.read(randomBytes, 0, randomBytes.length)

randomDevIStream.close()

randomNum = BigInteger(randomBytes)

say Rexx(randomNum.longValue()).right(24) '0x'Rexx(Long.toHexString(randomNum.longValue())).right(16, 0)

catch ex = IOException

ex.printStackTrace()

end

return

/*

To run the program in a loop 10 times from a bash shell prompt use:

for ((i=0; i<10; ++i)); do java <program_name>; done # Shell loop to run the command 10 times

*/

</lang>

'''Output:'''

<pre>

$ for ((i=0; i<10; ++i)); do java RRandomGen; done # Shell loop to run the command 10 times

-3724652236619320966 0xcc4f60865c70f17a

-8287324416757903696 0x8cfd8259e0b94eb0

-2951181559250748016 0xd70b4c02052cfd90

8171526404483923658 0x716717f863fd3eca

-4285529734202916706 0xc486bd699676009e

4783094698411310978 0x4260f74949dc3f82

6972277496665184225 0x60c28171482d97e1

-2382194670272317046 0xdef0be919c96f98a

7952058769071853043 0x6e5b6351938ecdf3

-1857830580859698636 0xe637a8ee0f000234

$

</pre>