When I do “uuidgen” in Unix how does it generate the ID?

Question

When I do "uuidgen" in Unix how does it generate the ID?

Answer 1

uuidgen comes from libuuid, which is part of e2fsprogs

The manual page for the e2fsprogs uuid_generate functtion states:

The uuid will be generated based on high-quality randomness from /dev/urandom, if available. If it is not available, then uuid_generate will use an alternative algorithm which uses the current time, the local ethernet MAC address (if available), and random data generated using a pseudo-random generator.