the value of the close-on-exec flag.
It is a FreeBSD specific constant and acts similarly as F_DUP2FD but set the FD_CLOEXEC flag in addition.
Duplicate a file descriptor to the minimum unused file descriptor greater than or equal to the argument.
The close-on-exec flag of the duplicated file descriptor is set. (Ruby uses F_DUPFD_CLOEXEC internally if available to avoid race condition. F_SETFD is used if F_DUPFD_CLOEXEC is not available.)
Determine whether a given region of a file is locked. This uses one of the F_*LK flags.
Return (as the function result) the capacity of the pipe referred to by fd.
Acquire a lock on a region of a file, waiting if necessary. This uses one of the F_*LCK flags
Change the capacity of the pipe referred to by fd to be at least arg bytes.
Open the file in non-blocking mode