You can lock flat files using the DTWF_OPEN and DTWF_CLOSE functions. With these functions, Net.Data reserves a flat file so that no other applications can read or update the file.
To lock a file, use the DTWF_OPEN function. This function ensures the file is unavailable to other applications and prevents the file from changing between the time it is read and updated.
To free the file, use the DTWF_CLOSE function. This function releases the file so that other applications can read or update the file.