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tryopen_try_to_open_the_file_.htm
Navigation:  ABC Library Reference > FileManager > FileManager Methods >====== TryOpen (try to open the file) C6H0009.jpg ====== Previous pageReturn to chapter overviewNext page

TryOpen, PROC

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The TryOpen method tells the FileManager the calling procedure is using the file, then OPENs the file if it is not already open. The TryOpen method does not attempt to handle errors that occur while opening the file.

The Open method provides a slightly different (automatic) alternative for opening files.

Implementation:

TryOpen tries to open the file. If it succeeds, it returns Level:Benign (declared in ABERROR.INC). If it fails, it returns the severity level of the error it encountered while trying to open the file. See Error Class for more information on severity levels.

Return Data Type:     BYTE

Example:

PROGRAM

INCLUDE('ABFILE.INC')            !declare FileManager class

MAP .                            !program map

GlobalErrors ErrorClass           !declare GlobalErrors object

Access:Client CLASS(FileManager)  !derive Access:Client object

Init      PROCEDURE               !prototype Access:File init

      END

!file declaration

Client  FILE,DRIVER('TOPSPEED'),PRE(CLI),CREATE,BINDABLE,THREAD

       END

CODE

GlobalErrors.Init                !initialize GlobalErrors object

Access:Client.Init               !initialize Access:Client object

IF Access:Client.TryOpen         !try to open the Client file

 MESSAGE('Could not open the Client file')   !handle the error yourself

 RETURN

END

!program code

Access:Client.Close              !close the Client file

Access:Client.Kill               !shut down the Access:Client object

GlobalErrors.Kill                !shut down the GlobalErrors object

See Also:     Open , OPEN

tryopen_try_to_open_the_file_.htm.txt · Last modified: 2021/04/15 15:57 by 127.0.0.1