lockf(2) - phpMan

flockfile (3)        - lock FILE for stdio
flockfile (3p)       - stdio locking functions
ftrylockfile (3)     - lock FILE for stdio
ftrylockfile (3p)    - stdio locking functions
funlockfile (3)      - lock FILE for stdio
funlockfile (3p)     - stdio locking functions
lockf (3)            - apply, test or remove a POSIX lock on an open file
lockf (3p)           - record locking on files
lockfile (1)         - conditional semaphore-file creator