In VB6 code i m using VBA.FileSystem.Dir to get file name from a directory path. But it is returning empty string. Please find the below code
Call getFile.ShowOpen //getFile is CommonDialog Control of VB6
txtFile.Text = getFile.FileTitle //Correct file name is returned
If Dir(getFile.filename) == "" Then
// Conditions come true..But ideally it should not!!!
But the file resides in some network location. Can there be any permission issue? If yes, How do i see that file in getFile.ShowOpen dialog and Dir() returns empty string?
Any help on what is wrong in the above code
Consider these points:
afaik, the double equal ( == ) is not supported in vb6
Dir = (whatever) can return ""
if whatever is a directory or hidden file
You could trap just the name by using
If Dir(whatever, vbDirectory Or vbHidden Or vbArchive Or vbNormal)
But you would still have to test each to see what it was.
btw, it's better to have a variable to receive Dir and inspect that, rather than inspecting Dir itself.
dim sTgt$
sTgt = Dir(whatever)
Also, btw, an alternative to chking each type is to to inspect FileLen.
Curiously, FileLen was not affected by the Hidden/Sys attribs, although it will err out if the file does not exist.
So, (and this is really old hacking stuff but handy code).
If you declare a variable for FileLen
Dim lfLen&
'and have some error coding
On Error resume next
'and then just inspect the target
lfLen = FileLen(stgt)
if lflen > 0 then
... do things
(or if hacking)
... binary open
Because, If the file no exist,
a directory will return 0,
but if file = archive, hidden, sys it will return bytes.
hth
Gary
Related
I have some code that uses System.IO to find files with a given extension. This works fine with regular folders but fails when the files are in Onedrive's local cache.
My assumption is that the problem is to do with the Onedrive cache folder because if the files are moved out of Onedrive and into a local folder e.g. c:\temp, it all works fine.
Dim Folder As New IO.DirectoryInfo(TextBox_RootFolder.Text)
Filelist = Folder.GetFiles("*.xlsx", IO.SearchOption.AllDirectories)
This is VB, so I believe there should not be any issues with string literals, so I'm stumped.
The path string comes out as something similar to: "C:\Users\user\OneDrive - ThisPlace\MyFolder" so there's nothing particularly weird about the string.
When presented with a folder on Onedrive, my variable 'Folder' is correctly assigned with the full path but an exception is thrown on calling Folder.Getfiles. This results in the error "The tag present in the reparse point buffer is invalid".
BTW, I'm a novice so example code would be really appreciated as a detailed technical explanation is likely to go whoosh over my head.
I'm please to report that I found an easy way to solve the problem.
Firstly I retained the code that uses Folder.Getfiles to provide a list of files as this is fast, elegant and retrieves files in sub-folders.
It still throws an exception when it encounters a cloud sync folder such as Onedrive, DropBox etc., so in the catch I use the Dir() function to loop through the files as this does not have problems with folders of this type.
Here is some pseudo-code to show an example:
Dim sFile As String
sFile = Dir(sPath + "\*.xlsx")
Do While sFile <> ""
[ do stuff here ]
sFile = Dir() '' Get the next file
Loop
I hope this is helpful to someone.
I have a file exists under this path:
//path/folder1/folder2/datafile.gdp
It is an input to an external program being called from vba in this manner:
Sub RunProgram()
Dim wsh As Object
SetCurrentDirectory "\\path\"
ChDir "\\path\folder1\folder2\" 'Set Directory
Set wsh = VBA.CreateObject("WScript.Shell")
check = CurDir
Statusnum = wsh.Run(Command:="program.exe ""\\path\folder1\folder2\datafile.gdp""", WindowStyle:=1, waitonreturn:=True)
But on the final line, including \path\folder1\folder2\ before the input file name appears to cause the external program to want to write some files into a duplicated directory that doesn't exist, causing an error. It used to work in this format before the .exe was updated by an external company. It now wants to write some files here, all prefixed with the name of my input file:
\\path\folder1\folder2\PATH\FOLDER1\FOLDER2\
Hoping to fix this, I changed the final line of the code to this, following some comments on a previous post here on SO:
Statusnum = wsh.Run(Command:="program.exe ""datafile.gdp""", WindowStyle:=1, waitonreturn:=True)
Since the directory is set correctly prior to calling the .exe, I thought removing the path for the input file would solve the issue.
The program now launches, but doesn't appear to load the input file with it and no longer runs calculations automatically in the background as it should. Instead, it launches and the main .exe window pops up to the user as if it had just been launched for setting up a new project, calculations don't occur automatically.
To check which directory the VBA code was try to pull my datafile.gdp from, I created these loops directly before calling the .exe:
If Len(Dir("\\path\folder1\folder2\datafile.gdp")) = 0 Then
FileIsMissing1 = True 'I use Excel-VBA watches to break if true
End If
If Len(Dir("datafile.gdp")) = 0 Then
FileIsMissing2 = True
End If
Bizarrely, neither of these loops causes a break. The file only exists in
\\path\folder1\folder2\datafile.gdp
Not in the duplicated directory... so why are both of these statements satisfied? Does entering the directory make no difference even when the current directory has been set? The current directory seems to be impacting the line:
Statusnum = wsh.Run(Command:="program.exe ""\\path\folder1\folder2\datafile.gdp""", WindowStyle:=1, waitonreturn:=True)
But not these if loops, and I'm not sure why.
I'm making a console application and I want to see what files is in a folder
For Each foundFile As String In My.Computer.FileSystem.GetFiles("c:\users\zac\desktop\booked vehicle\requested\")
Console.WriteLine(foundFile)
Next
after using this code and find that the folder is empty I need an If statement that say's
If foundfile has no files then
tell user no files found
end if
but I don't know how to write this so Visual Basic understands.
Load the files into a variable then check the count.
Dim files = My.Computer.FileSystem.GetFiles("c:\users\zac\desktop\booked vehicle\requested\")
If files.Count = 0 Then
'tell user no files
Else
For Each file In files
Console.WriteLine(file)
Next
End If
FileSystem.GetFiles() returns a collection of file name strings. As OneFineDay showed, you can use the collection's Count property to know if any files were found.
The downside of using FileSystem.GetFile() is that it has to search the entire folder before then returning the entire list of filenames. If you are searching large folders and speed is an issue, consider using Directory.EnumerateFiles() instead. That way, you can output a message if no file was found, otherwise loop throuh the list of found files. For example:
Dim files = Directory.EnumerateFiles("c:\users\zac\desktop\booked vehicle\requested\").GetEnumerator()
If files.MoveNext Then
' files were found
Do
Console.WriteLine(files.Current)
Loop Until Not files.MoveNext
Else
' no files were found
End If
I personally would use Linq to accomplish this. It's very quick and efficient to use in this case. I put the Console.ReadLine() at the end to show the files, you can remove this if need to be. Also you can change the Console.WriteLine to not include the string (s) if you don't want to. The s was declared if you want to show the files and also to see if there are any files. As I said, this was for my viewing to see the files. Straight to the point!
Dim s As String = String.Join(Environment.NewLine, New DirectoryInfo("YOUR DIRECTORY").GetFiles().[Select](Function(file) file.Name).ToArray)
Console.WriteLine(If(s.Length > 0, s, "No files found!"))
Console.ReadLine()
I check for the existence of the file with File.Exists(filePath). Then I try to open the file from within Excel with Excel.Workbooks.OpenText(filePath). But Excel complains that the file's not there. What the heck?
The context is that I am shelling out to another application to process a given file and produce a .out file, which I then convert to an Excel workbook.
'' At this point, filePath is a .txt file.
Dim args As String = String.Format("""{0}""", filePath)
...
Dim exe As String = Config.ExtractEXE
Dim i As New ProcessStartInfo(exe)
i.Arguments = args
Dim p As Process = Process.Start(i)
p.WaitForExit()
...
'' filePath now becomes the .out file.
'' Then eventually, I get around to checking:
'If Not File.Exists(filePath) Then
' MsgBox("Please ensure...")
' Exit Sub
'End If
'' In response to an answer, I no longer check for the existence of the file, but
'' instead try to open the file.
Private Function fileIsReady(filePath As String) As Boolean
Try
Using fs As FileStream = File.OpenRead(filePath)
Return True
End Using
Catch
Return False
End Try
End Function
Do Until fileIsReady(filePath)
'' Wait.
Loop
ExcelFile.Convert(filePath...)
'' Wherein I make the call to:
Excel.Workbooks.OpenText(filePath...)
'' Which fails because filePath can't be found.
Is there a latency issue, such that .Net recognizes the existence of the file before it's accessible to other applications? I just don't understand why File.Exists() can tell me the file is there and then Excel can't find it.
As far as I know, the only application that might have the file open is the application I call to do the processing. But that application should be finished with the file by the time p.WaitForExit() finishes, right?
I've had to deploy the application with this as a known bug, which really sucks. There's an easy workaround for the user; but still--this bug should not be. Hope you can help.
Whether or not a file exists is not the only factor in whether you can open it. You also need to look at file system permissions and locking.
File.Exists can lie to you (it returns false if you pass a directory path or if any error occurs, even if the file does exist)
The file system is volatile, and things can change even in the brief period between an if (File.Exists(...)) line and trying to open the file in the next line.
In summary: you should hardly ever use file.exists(). Almost any time you are tempted to do so, just try to open the file and make sure you have a good exception handler instead.
Using VBA, how can I:
test whether a file exists, and if so,
delete it?
1.) Check here. Basically do this:
Function FileExists(ByVal FileToTest As String) As Boolean
FileExists = (Dir(FileToTest) <> "")
End Function
I'll leave it to you to figure out the various error handling needed but these are among the error handling things I'd be considering:
Check for an empty string being passed.
Check for a string containing characters illegal in a file name/path
2.) How To Delete a File. Look at this. Basically use the Kill command but you need to allow for the possibility of a file being read-only. Here's a function for you:
Sub DeleteFile(ByVal FileToDelete As String)
If FileExists(FileToDelete) Then 'See above
' First remove readonly attribute, if set
SetAttr FileToDelete, vbNormal
' Then delete the file
Kill FileToDelete
End If
End Sub
Again, I'll leave the error handling to you and again these are the things I'd consider:
Should this behave differently for a directory vs. a file? Should a user have to explicitly have to indicate they want to delete a directory?
Do you want the code to automatically reset the read-only attribute or should the user be given some sort of indication that the read-only attribute is set?
EDIT: Marking this answer as community wiki so anyone can modify it if need be.
An alternative way to code Brettski's answer, with which I otherwise agree entirely, might be
With New FileSystemObject
If .FileExists(yourFilePath) Then
.DeleteFile yourFilepath
End If
End With
Same effect but fewer (well, none at all) variable declarations.
The FileSystemObject is a really useful tool and well worth getting friendly with. Apart from anything else, for text file writing it can actually sometimes be faster than the legacy alternative, which may surprise a few people. (In my experience at least, YMMV).
I'll probably get flamed for this, but what is the point of testing for existence if you are just going to delete it? One of my major pet peeves is an app throwing an error dialog with something like "Could not delete file, it does not exist!"
On Error Resume Next
aFile = "c:\file_to_delete.txt"
Kill aFile
On Error Goto 0
return Len(Dir$(aFile)) > 0 ' Make sure it actually got deleted.
If the file doesn't exist in the first place, mission accomplished!
The following can be used to test for the existence of a file, and then to delete it.
Dim aFile As String
aFile = "c:\file_to_delete.txt"
If Len(Dir$(aFile)) > 0 Then
Kill aFile
End If
In VB its normally Dir to find the directory of the file. If it's not blank then it exists and then use Kill to get rid of the file.
test = Dir(Filename)
If Not test = "" Then
Kill (Filename)
End If
set a reference to the Scripting.Runtime library and then use the FileSystemObject:
Dim fso as New FileSystemObject, aFile as File
if (fso.FileExists("PathToFile")) then
aFile = fso.GetFile("PathToFile")
aFile.Delete
End if
Here's a tip: are you re-using the file name, or planning to do something that requires the deletion immediately?
No?
You can get VBA to fire the command DEL "C:\TEMP\scratchpad.txt" /F from the command prompt asynchronously using VBA.Shell:
Shell "DEL " & chr(34) & strPath & chr(34) & " /F ", vbHide
Note the double-quotes (ASCII character 34) around the filename: I'm assuming that you've got a network path, or a long file name containing spaces.
If it's a big file, or it's on a slow network connection, fire-and-forget is the way to go.
Of course, you never get to see if this worked or not; but you resume your VBA immediately, and there are times when this is better than waiting for the network.
You can set a reference to the Scripting.Runtime library and then use the FileSystemObject. It has a DeleteFile method and a FileExists method.
See the MSDN article here.
A shorter version of the first solution that worked for me:
Sub DeleteFile(ByVal FileToDelete As String)
If (Dir(FileToDelete) <> "") Then
' First remove readonly attribute, if set
SetAttr FileToDelete, vbNormal
' Then delete the file
Kill FileToDelete
End If
End Sub