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Re: [Condor-users] Reading /dev/random



Hi,

there is a document explaining how Condor is replacing the calls by name, with a call by number to catch it. When there is already the number in your program, most likely Condor will not replace it, and it will be executed on the nodes.

http://www.cs.wisc.edu/condor/doc/ckpt97.pdf

Page 5, Chapter 3.4.1

So, maybe something like syscall(SYS_read, fd, buf len) (and for open, close, etc.) will work for you, when you use it in your program directly.

Cheers - Reuti



Olaf Lenz wrote:
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Hello!

Alain EMPAIN wrote:
| If you use a wrapper script to build the command file, it will be easy
| to provide an ever changing random value to the executable if you put it
| inside every job arguments, before the queue command.

Thanks for the hint, but this does not really solve the problem.

Of course there are plenty workarounds to get random numbers, even from
/dev/random - for example I could create a file that contains numbers
from /dev/random, or I could pass the seed as an argument (as you
suggested), or I could use the random() function, etc.

However, this does not really solve the problem that the semantics of
the fread() command is changed by the condor wrapper.

Olaf
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