[RESOLVED] Open a file with wrong extension

[Ellis Dee]

ShellExecute works great, but the problem I have is that the file doesn't have the correct extension.

As an example, let's say I want to open "file_id.diz" with Word. I specifically do not want to rename it to "file_id.doc", even temporarily.

What is the best way to accomplish this?

[RealityRipple]

Shell Word with the file as its Paramaters, or set .diz to a MSWord filetype.

WordPath = "C:\Program Files\Microsoft Office\OFFICE11\WINWORD.exe"
Shell WordPath & " """ & ToOpen & """", vbNormalFocus

Something like that?

[Ellis Dee]

I won't know what the default program is to open the file, and the extension is associated with my program so I can't change the association in Windows.

ShellExecute is perfect for this except that it needs the filename to be the correct extension.

[zynder]

How about? just an alternative.

Dim oWord As Word.Application
Dim oDoc As Word.Document


Private Sub Command1_Click()
    Set oWord = New Word.Application
    Set oDoc = New Word.Document
    
    oDoc.Application.Documents.Open "c:\file_id.diz"
  
End Sub


Private Sub Form_Unload(Cancel As Integer)
    oWord.Quit False
    Set oDoc = Nothing
    Set oWord = Nothing
End Sub

[Ellis Dee]

To clarify with a different example, let's say they're mpg audio files, (they aren't, but it gives you an idea) named with a custom extension to associate them with my program.

I want my program to be able to open the mpg file using whatever the computer normally uses to play mpg files. It could be WinAmp, Windows Media Player, RealPlayer, or anything.

That's the beauty of ShellExecute: I don't have to worry about what the program actually is, because it just lets the OS sort it out.

Can I somehow hack into the ShellExecute command line without actually executing it? Or is there another way?

I'm perfectly comfortable looking up the file extension in the registry (under ClassesRoot) and generating the command line manually. But from what I can tell that won't work reliably under Vista. So I'm hoping for an alternative.

Also, these files range in size anywhere from 25k to 25 megs, and they could be burned to a CD. That's why I don't want to rename or copy them. (It would take too long to copy 25 megs from the CD to the hard drive, and you can't rename files on a CD-R disc.)

[Hack]

Where do these files come from? How do they get created?

[Ellis Dee]

Where do these files come from? How do they get created?

They may or may not be created from scratch by the user, and can be any file he can create using any program he has on his computer.

[Hack]

Ok.....that wasn't what I was expecting to hear , but it does lead to another question.

If these are user created files, how do they get the extention .diz? Wouldn't user created files have their default extension?

[Ellis Dee]

Ok.....that wasn't what I was expecting to hear , but it does lead to another question.

If these are user created files, how do they get the extention .diz? Wouldn't user created files have their default extension?

heh. Think of it as a backup, if that helps. Or a version control program.

Note that the .diz and .mp3 examples are not the actual files; they're just examples. (file_id.diz is an oldschool filename; I used it for nostalgia.) The actual files are from another program. Well, set of programs.

It's fairly involved, to be honest. Let's just say that I need to be able to execute a program the same way ShellExecute does, but the file has the wrong extension.

Given a 25 meg file burned to a CD-R as MyFile.abc, I need to ShellExecute it as MyFile.xyz without disturbing the OS's existing *.abc association. What is the best way to accomplish this?

Note that when it gets executed/opened, whatever program just opened it should see it as MyFile.abc, not MyFile.xyz.

For example, if you create a text file and name it file_id.diz, then right-click it and "Open With" notepad, notepad recognizes the file as named *.diz, not *.txt.

[Al42]

1) You MUST save the original extension somewhere. A filetype that's unknown has no app associated with it. (Every possible 3-letter combination probably has an app associated with it, but that's beside the point.)

2) Use the FindExecutable API to find the app associated with the original extension on that computer. Shell the app with the file as the param.

[Ellis Dee]

Use the FindExecutable API to find the app associated with the original extension on that computer. Shell the app with the file as the param.

Sweet, this is exactly what I was looking for. Sadly, I still need a little help. Could you or someone else help flesh out this function?

Private Declare Function FindExecutable Lib "shell32.dll" Alias "FindExecutableA" (ByVal lpFile As String, ByVal lpDirectory As String, ByVal lpResult As String) As Long

' pstrFile contains full path and filename ("c:\File_id.diz")
' pstrExt contains original extension ("txt")
Public Sub RunFile(pstrFile As String, pstrExt As String)
    Dim strFake As String

   strFake = Left(pstrFile, InstrRev(pstrFile, ".")) & pstrExt
   ' Now what?
End Sub

[DigiRev]

Try this:

Option Explicit

Private Declare Function FindExecutable Lib "shell32.dll" Alias "FindExecutableA" (ByVal lpFile As String, _
    ByVal lpDirectory As String, ByVal lpResult As String) As Long

' pstrFile contains full path and filename ("c:\File_id.diz")
' pstrExt contains original extension ("txt")
Public Function RunFile(pstrFile As String, pstrExt As String) As String
    Dim strFake As String, strRet As String
    Dim lonRet As Long
    
    strFake = Left$(pstrFile, InStrRev(pstrFile, ".")) & pstrExt
    ' Now what?
   
    strRet = String$(255, Chr$(0))
    lonRet = FindExecutable(strFake, vbNullString, strRet)
    
    If lonRet > 32 Then
        RunFile = Left$(strRet, InStr(strRet, Chr$(0)) - 1)
    End If

End Function

Private Sub Form_Load()
    Dim strPath As String
    
    strPath = RunFile("C:\test\test.diz", "txt")
    MsgBox strPath
    'ShellExecute strPath here.
End Sub

[Ellis Dee]

FindExecutable appears to only work if the file exists on disk.

While I can create one empty dummy file for every extension in the database, that's pretty inelegant and wasteful. It's also less than desirable for other reasons specific to my project.

Any other ways to solve the OP?

Speaking of which, what's the deal with Vista and the registry? It seems that my existing solution of creating the command line based on the ClassesRoot file association in the registry is the only way to really achieve what I'm looking for. I'm concerned about it working under Vista, (thus my reason for posting this thread,) but if it'll still work under Vista, I'll just keep it as-is. Here's the current steps that I do, using Excel xls files as an example:

Query ClassesRoot\.xls
- Remember the (default) value (Excel.Sheet.8) for next step
Query ClassesRoot\Excel.Sheet.8\Open\Shell\Command
- The (default) value holds the command line to open that type of file

In this case, it's "C:\Program Files\Microsoft Office\Office10\EXCEL.EXE" /e

I then slap the filename (with the wrong extension) to the end of that and shellexecute it. Works great under XP; will it work under Vista?

ETA: Note that most of the ClassesRoot\<Type>\Shell\Open\Command registry entries include a "%1" placeholder somewhere in the string to allow easy insertion of the desired filename. I'm not completely sure why Microsoft Office programs like Excel and Word don't inlcude a %1 in their command line, but whatever. They get to be different I guess.

[Al42]

FindExecutable appears to only work if the file exists on disk.

While I can create one empty dummy file for every extension in the database, that's pretty inelegant and wasteful. It's also less than desirable for other reasons specific to my project.

Any other ways to solve the OP?

Create an empty dummy file just before running FindExecutable, then delete it.

ETA: Note that most of the ClassesRoot\<Type>\Shell\Open\Command registry entries include a "%1" placeholder somewhere in the string to allow easy insertion of the desired filename. I'm not completely sure why Microsoft Office programs like Excel and Word don't inlcude a %1 in their command line, but whatever. They get to be different I guess.

Strange, since Excel can be run with an argument (it looks at its command line).

[Ellis Dee]

Create an empty dummy file just before running FindExecutable, then delete it.

Yeah, that's probably my best bet.

My original concern was that if the program should fail for whatever reason -- eg: the user decides to End Task -- I don't want dummy files left laying around.

But if I create the dummy file the line before the FindExecutable call, then delete it the line after, that's pretty much as secure as it gets.

Thanks much, Al42.

[techgnome]

Crazy question.... if the file has the"wrong" extension..... how are you going to know WHAT app to open it with.... For instance.... I have a word doc.... I change the extension form DOC to MP9..... there's no way to know that it's a Word Doc.

or am I still missing something?

-tg

[Ellis Dee]

Crazy question.... if the file has the"wrong" extension..... how are you going to know WHAT app to open it with

The original extension is stored in a database.