How to release locked input files?

Getting Started
1

I am busy writing a desktop application which reads downloaded info files every 2 minutes. Because these files are coming from the internet it can happen that something goes wrong (communication, xfer error or what) that the file does have zero bytes.
I have a check on such files to leave zero byte files aside and not use them:

try
f = GetFolderItem(aFile)
catch err as NilObjectException
Logs(“AnalyzeFileEQ”,“Error: “+cStr(err)+” occurred at “+d.ShortDate+”/”+d.LongTime+" for file: "+aFile)
end try

and a second one incase the err does not occur:

If f <> Nil And f.Exists then
if f.Length = 0 then
NoInfos = true
NoInfo=NoInfos
exit
else
NoInfos = False
NoInfo=NoInfos
NoInfoTeller = 0

      textInput = TextInputStream.Open(f)
      textInput.Encoding = Encodings.MacRoman
      
      //analyze the inputfile and store values in the apropriate variables till the end of file
      While Not textInput.EOF
        RLine= textinput.ReadLine

.
.
.
normally this responds good, but I have that phenomenon that after a day the files will not be overwritten anymore and the date/time stamp defers for hours. The only way to release the “locked” file is to quit the application and start it again. Than always the file can be removed or overwritten.

I tried to use TextinputStream.Close () and TextinputStream.Close (f), but that all resulted in the error: Static reference to instance method: call this on an instance of class TextInputStream.

Is there a way to release these input files?

2

The correct syntax is to use your variable name.

textInput.Close

You should also nil out the variable

textInput.Close
textInput = Nil
3

Ok, I used this one…

The line above and then:

.
.
While Not textInput.EOF
RLine= textinput.ReadLine
.
.
. wend
textinput.close

==> NilObjectException

I did not close the file before the statement. First I do after the readline loop is the textinput.close

Where do I go wrong?

4

Well I deal with text files in this manner, maybe it’s helpful for your purpose. TargetFile is your FolderItem, FileContent is the content you can run checks against. Dont forget to check Encodings first.

[code] try

			dim FileContent as String
			dim SourceStream as TextInputStream
			
			if TargetFile <> Nil then
					
					SourceStream = TextInputStream.Open(TargetFile)
					
					if SourceStream <> Nil then
							
							FileContent = SourceStream.ReadAll
							SourceStream.Close
							
					end if
					
			end if
			
			TargetFile = nil
			SourceStream = nil
			
	catch
			
	Finally
			
	end try[/code]
5

Thank you Tomas for your solution. I adjusted all parts where files are read with the try…catch…finally…end try entries and now all files are released. When file contents was not received from the internet, the empty file can be manually removed or will be automatically overwritten with the new file of the next run. Just as expected. :smiley:

6

In the documentation examples (TextInputStream / TextInputStream, and BinaryStream).