Fuzzing Irssi

I&#x27;m new to fuzzers and fuzz testing in general so I apologise for my ignorance about the purpose of fuzzing. My understanding is that fuzzing tests the user facing side (which is what is important for most programs). Does there exist similar tooling for testing the system-facing side (i.e. the stack below your application) to check your applications error handling, for example and uncover corner cases. What I&#x27;m getting at it something like syzkaller but for userspace, so library functions beneath your application would return wrong values and you get to see how your application responds to them.<p>Sorry for the bad English.

This notes that they disabled reading config files in order to own life as the default setup. I assume that with more time it would be wise to try and fuzz as many configured options as possible as well?

This fuzzing is interesting stuff. Does anyone know of an in-process or otherwise lib for the JVM? Findbugs is mentioned in here but I&#x27;m not sure if that does fuzzing (maybe a plugin?).<p>Seems in my mind to be a nice complement to achieving code-coverage with testing i.e. whereas unit&#x2F;integration testing might test the various code paths with a few good&#x2F;bad values, this then throws every possible input value at them to see what breaks.