https://man.openbsd.org/flock.2 https://man.openbsd.org/flock.2 https://man7.org/linux/man-pages/man2/flock.2.html https://man7.org/linux/man-pages/man2/flock.

https://man.openbsd.org/flock.2 https://man.openbsd.org/flock.2 https://man7.org/linux/man-pages/man2/flock.2.html https://man7.org/linux/man-pages/man2/flock.2.html