flock

A version of flock is implemented on top of fcntl(2) locking. It does not provide complete binary compatibility, and the following differences exist between this version and the SunOS 4.x version:

• flock requires the file to be opened for writing before requesting an exclusive lock.

• Read permission is required on the file to obtain a shared lock.

• Locking a segment that is already locked by the calling process causes the old lock type to be removed and the new lock type to take effect.

• Locks are not inherited by a child process in a fork function.

• Locks obtained through the flock mechanism under SunOS 4.x were known only within the system on which they were placed. This is no longer true.

The SunOS 4.x behavior is not available in the default Solaris 2.x release or with this package.