_File$ is not behaving as expected, cannot determine why

[hanness]

I'm having some difficulties with _Files$ not behaving as expected. A detailed description of the issue can be found in the comments of the code sample below.

To summarize briefly, _Files$ works fine by itself, but when I introduce a number of lines of code that I currently have commented out, those lines for some unknown reason cause _Files$ to no longer work. Again, see the full description in the comments.

My test scenario:

QB64PE 3.14.1
Windows 11 24H2, latest public release (build 26100.2033)
Logged on as an Administrator

If anyone can provide a clue why this is failing, I would really appreciate some insight. I've been at this for a few hours and cannot put my finger on the problem.

Code: (Select All)

$Debug

$Console:Only

Option _Explicit



Dim MountedImageDriveLetter As String

Dim Cmd As String

Dim GetLine As String

Dim count As Integer

Dim FullPathToImage As String

Dim ISO_Path As String

Dim CurrentFile As String

Dim ff1 As Long

Dim FileSpec As String



' This program is placed in a folder that contains a number of files including files that take the form

' "EXPORTED DRIVERS*.iso". The program is supposed to mount each ISO image file (the first powershell command),

' and then it runs another command sending the output of that command to a file called MountInfo.txt. Next,

' we open MountInfo.txt and read 4 lines. The 4th line will contain the drive letter to which the ISO image was

' mounted. We save the drive letter and a colon (D: as an example) in MountedImageDriveLetter$. We then close

' MountInfo.txt and delete it. As a confirmation we print the drive letter to the screen.

'

' Here now is where the problem begins: We use _File$ to retrieve the next file matching the pattern

' "EXPORTED DRIVERS*.iso". However, upon running this command it returns an empty string rather than the next

' file name. Why???? For the life of me I cannot figure it out!



' Please note that I have commented out all of the lines that do the heavy lifting. In the current state, this

' program simply gets the first file name, prints it to the screen, then it gets the next file name. This works

' flawlessly! But when I uncomment all the lines in the DO loop the line "CurrentFile$ = _Files$" simply returns

' an empty string.



' TIP: I suggest running this in debug mode and then start the program paused. Press F4 and add all variables

' to watch. Then press F7 to step through one line at a time. You will see that the first file name is retrieved

' correctly, but when you reach line 68 it fails to get the next file name when the lines in the DO loop are

' uncommented but it does work with those lines commented out.



' Make sure to create a number of files with a .iso extension in the same folder with the program. These should

' be real ISO image files because we are actually mounting them with this program.



ISO_Path$ = _CWD$



FileSpec$ = ISO_Path$ + "\EXPORTED DRIVERS*.iso"



CurrentFile$ = _Files$(FileSpec$)



Do While Len(CurrentFile$) > 0

    '    MountedImageDriveLetter$ = ""

    '    FullPathToImage$ = ISO_Path$ + "\" + CurrentFile$



    '    Cmd$ = "powershell.exe -command " + Chr$(34) + "Mount-DiskImage " + Chr$(34) + "'" + FullPathToImage$ + "'" + Chr$(34) + Chr$(34) + " > NUL"

    '    Shell Cmd$

    '    Cmd$ = "powershell.exe -command " + Chr$(34) + "Get-DiskImage -ImagePath '" + FullPathToImage$ + "' | Get-Volume" + Chr$(34) + " > MountInfo.txt"

    '    Shell Cmd$



    '    ff1 = FreeFile

    '    Open "MountInfo.txt" For Input As #ff1



    '    For count = 1 To 4

    '        Line Input #ff1, GetLine$

    '    Next count



    '    MountedImageDriveLetter$ = Left$(GetLine$, 1) + ":"

    '    Close #ff1

    '    Kill "MountInfo.txt"



    '    Print MountedImageDriveLetter$

    Print CurrentFile$



    CurrentFile$ = _Files$

Loop





End