flock(3S)

flock: flockfile, ftrylockfile, funlockfile -- standard I/O synchronization functions

Synopsis

#include <stdio.h>

void flockfile(FILE

file);

void funlockfile(FILE

file);

int ftrylockfile(FILE

file);

Description

These functions provide for explicit application-level locking of standard I/O stream objects. They are used by a thread to delineate a sequence of I/O statements that are to be executed as a unit.

flockfile: grants thread ownership of a file, suspends thread until ownership is granted
ftrylockfile: similar to flockfile, except that it returns a value for success or failure
funlockfile: relinquishes file ownership granted to a thread by a previous successful call to flockfile or ftrylockfile

References

flockfile(3S), ftrylockfile(3S), funlockfile(3S), Intro(3S)