Chris's Wiki :: blog/linux/FlockFcntlAndNFSUnix broadly and Linux specifically has long had three functions that can do file locks, flock(), fcntl(), and lockf(). The latter two are collectively known as 'POSIX' file locks because they appear in the POSIX specification (and on Linux lockf() is just a layer over fcntl()), while flock() is a separate thing with somewhat different semantics (cf), as it originated in BSD Unix. In /proc/locks,
