The open function declares the start of output to the printer and specifies the printer information file. To output data to the printer, always execute the open function before using other functions. In Figure 3.2, the following statement opens the printer:
OPEN OUTPUT print-file
File identifier specified in ASSIGN clause: Printer information file name
FILE STATUS clause: Return code storage area for abnormal termination of the open process
After the operation is complete, be sure to close the file opened by the application program. If it is not closed, data is not printed and internal resources can remain allocated.
