Myths about /dev/urandom posted December 2014
In one of my class the teacher advise against
I wondered why. I remembered reading some articles about random vs urandom and urandom being better, but that was years ago and my memory is not fresh. Wikipedia does advise against it, as does the manpage if you want to generate a long term key.
Fact: /dev/urandom is the preferred source of cryptographic randomness on UNIX-like systems.