#debug display

[Steve Bouffe]

I use this function to open files and return the error code if needed.

Other processes have acces to the file so the function allows for this and wait for a max of 20 seconds (more than enough time for other processes to finish)

I added the statement #DEBUG DISPLAY ON

I had an error display message today showing un untrapped error 70 in this function.

Can't see why the code should produce this, an I using ON ERROR RESUME NEXT correctly?

FUNCTION Open_Seq_In( BYVAL Han AS LONG, BYVAL SharedMode AS LONG, FileSpec AS STRING ) AS LONG
	'
	' SharedMode = 1 if open in shared read
	LOCAL ErrCount AS LONG
	'
	ErrCount = 0
	DO
		ERRCLEAR
		ON ERROR RESUME NEXT
		IF SharedMode = 0 THEN
			OPEN FileSpec FOR INPUT ACCESS READ LOCK READ WRITE AS Han
		ELSE
			OPEN FileSpec FOR INPUT ACCESS READ LOCK SHARED AS Han
		END IF
		IF ERR = 0 OR ErrCount = 80 OR ERR <> 70 THEN
			EXIT DO
		END IF
		INCR ErrCount
		SLEEP 250
	LOOP
	'
	FUNCTION = ERR
	'
END FUNCTION

[Dave Biggs]

You should get a display message showing an "untrapped error 70" up to as many as 80 times if SharedMode = 0 and the file is in use by another process for that many iterations of the loop.

On Error Resume Next does nothing in this sub as error trapping (ON ERROR GOTO {label | line_number} ) hasn't been used to turn error trapping on..

To disable error trapping, use ON ERROR GOTO 0 or ON ERROR RESUME NEXT. You can use this technique if an error occurs for which you have not defined a recovery path; you can also choose to display the contents of ERR or ERRCLEAR at this time.

You can use this to test - run it twice (without clearing the first message box)..

Function PBMain()
 Dim sTest$
 Dim Han&
  Err = Open_Seq_in (Han, 0, EXE.Name$ + ".bas")
  sTest = Str$(Err) + " * " + Error$(Err)
  MsgBox sTest$,,"Result"
 
End Function
'------------------/PBMain

[Steve Bouffe]

Changed the function using TRY & CATCH

FUNCTION Open_Seq_In( BYVAL Han AS LONG, BYVAL SharedMode AS LONG, FileSpec AS STRING ) AS LONG
'
' SharedMode = 1 if open in shared read
'
LOCAL ErrCount AS LONG
'
DO
'
TRY ' <o><o><o><o> TRY ERROR TRAP <o><o><o><o>
'
ERRCLEAR
'
IF SharedMode = 0 THEN
OPEN FileSpec FOR INPUT ACCESS READ LOCK READ WRITE AS Han
ELSE
OPEN FileSpec FOR INPUT ACCESS READ LOCK SHARED AS Han
END IF
'
CATCH ' <o><o><o><o> CATCH ERROR TRAP <o><o><o><o>
'
IF ErrCount = 80 OR ERR <> 70 THEN
FUNCTION = ERR
EXIT FUNCTION
END IF
'
INCR ErrCount
SLEEP 250
'
FINALLY ' <o><o><o><o> FINALLY ERROR TRAP <o><o><o><o>
'
IF ERR = 0 THEN
EXIT FUNCTION
END IF
'
END TRY ' <o><o><o><o> TRY END ERROR TRAP <o><o><o><o>
'
LOOP
'
END FUNCTION

[Dave Biggs]

No "Untrapped errors" now with my tests