The FCONTROL intrinsic's controlcode parameter
settings identify the control operation desired.
A setting of 2 ensures that the requested output has been physically
completed. (If the file is shared, you must lock the file before
calling the FCONTROL intrinsic with a control code of 2.) A control
code of 6 provides a similar function. It ensures that the requested output
has been physically completed and that the end-of-file has been written.
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