Visual FoxPro

Generating Repeatable Random Data for Testing/Debugging

See more PRNG Examples

Demonstrates how to use the Fortuna PRNG to generate random-looking but repeatable non-random data for the purpose of testing and debugging. Visual FoxPro

LOCAL lnSuccess
LOCAL loFortuna
LOCAL lcStrRandHex
LOCAL lcStrRandBase64
LOCAL lcStrRandBase58
LOCAL loFortuna2

lnSuccess = 0

* This example assumes the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

lnSuccess = 0

loFortuna = CreateObject('Chilkat.Prng')

* Normally an application would seed the PRNG with entropy from
* some real random source.  However, sometimes we want the same
* random sequence of bytes for testing and debugging purposes.
* This a reason why GetEntropy and AddEntropy are two different methods.
* An application could omit the call to GetEntropy, and instead pass
* non-random data to AddEntropy. For example:

* Seed the PRNG with non-entropy, so we get a repeatable sequence.
* Note: AddEntropy can be called any number of times.
lnSuccess = loFortuna.AddEntropy("01020304","hex")
lnSuccess = loFortuna.AddEntropy("hello world","ascii")

* Generate some random data:
lcStrRandHex = loFortuna.GenRandom(16,"hex")
lcStrRandBase64 = loFortuna.GenRandom(22,"base64")
lcStrRandBase58 = loFortuna.GenRandom(32,"base58")

? "hex random bytes: " + lcStrRandHex
? "base64 random bytes: " + lcStrRandBase64
? "base58 random bytes: " + lcStrRandBase58

* Try it again with a different object to verify that the same results are obtained:
loFortuna2 = CreateObject('Chilkat.Prng')

lnSuccess = loFortuna2.AddEntropy("01020304","hex")
lnSuccess = loFortuna2.AddEntropy("hello world","ascii")

lcStrRandHex = loFortuna2.GenRandom(16,"hex")
lcStrRandBase64 = loFortuna2.GenRandom(22,"base64")
lcStrRandBase58 = loFortuna2.GenRandom(32,"base58")

? "hex random bytes: " + lcStrRandHex
? "base64 random bytes: " + lcStrRandBase64
? "base58 random bytes: " + lcStrRandBase58

RELEASE loFortuna
RELEASE loFortuna2