--fsize for stdout about isolate HOT 7 CLOSED

If your stdout is a file then yes, it is expected behavior, because --fsize affects all files. If it is not a file, let me know, it could be a bug.

from isolate.

In my program I don't open any files. I just specified output with -o flag in isolate.

I noticed that these two commands limit file size to 1MB:

$ isolate --fsize 1 -i input.txt -o output.txt --run -- a.out
$ isolate --fsize 1 -i input.txt --run -- a.out > output.txt

But this one doesn't:

$ isolate --fsize 1 -i input.txt --run -- a.out | dd of=output.txt

Also, on my machine this command sometimes generates output.txt, and sometimes doesn't:

$ isolate --fsize 1 -i input.txt --run -- a.out | tee output.txt

from isolate.

In the third example, the output file is generated by "dd", which runs outside the sandbox, so it is not limited by the sandbox in any way. On the contrary, in the first two examples, the file is written to by the program running inside the sandbox, so the limit applies.

The fourth example should behave deterministically. If the output file is not generated, does any error message appear?

from isolate.

I don't get any error messages for fourth example.

from isolate.

from isolate.

Why it wouldn't be? 😄 Yes, I tried running this many times. Can you try it on your machine? Any program that outputs something to stdout will do the job.

from isolate.

I just ran the following test:

set -e ; while true ; do rm -f /tmp/1 && bin/isolate --fsize 1 --run -- /bin/echo brequequex | tee /tmp/1 && est -s /tmp/1 ; done

Even after several thousand tries, it did not fail. Also, I see no reason why tee not creating a file when running outside sandbox could be related to isolate in any way.

I am closing this issue, but if you have any other data confirming the problem, feel free to re-open it.

from isolate.