How to check if a file/folder exists in the C drive VB.NET

Question

i'm trying to create a simple anti-cheat which detects external cheats in all the C drive, but i don't know how to check if a determinate file exists in all the C drive, any help?

Answer 1

Here is code that I adapted from How to: Iterate Through a Directory Tree. In the example, the FileExists() function returns True if the file bit32.txt is found anywhere on the C drive. Not all files and directories may be accessible. In that case, the function display the paths of these files and directories. You may want to adapt the code to do whatever you want in these cases.

Imports System.IO

Module Module1

    Private Sub Main(ByVal args() As String)
        Dim exists As Boolean = FileExists(New DriveInfo("C").RootDirectory, "bit32.txt")
    End Sub

    Private Function FileExists(ByVal root As DirectoryInfo, ByVal filename As String) As Boolean
        Dim files() As FileInfo = Nothing
        Dim subDirs() As DirectoryInfo = Nothing
        ' First, process all the files directly under this folder
        Try
            files = root.GetFiles("*.*")
        Catch e As Exception
            ' This code just writes out the message and continues to recurse.
            ' You may decide to do something different here. For example, you
            ' can try to elevate your privileges and access the file again.
            Console.WriteLine(e.Message)
        End Try

        If (Not (files) Is Nothing) Then
            For Each fi As FileInfo In files
                ' In this example, we only access the existing FileInfo object. If we
                ' want to open, delete or modify the file, then
                ' a try-catch block is required here to handle the case
                ' where the file has been deleted since the call to TraverseTree().
                'Console.WriteLine(fi.FullName);
                If (fi.Name = filename) Then
                    Return True
                End If

            Next
        End If

        Try
            ' Now find all the subdirectories under this directory.
            subDirs = root.GetDirectories
            For Each dirInfo As DirectoryInfo In subDirs
                ' Resursive call for each subdirectory.
                If FileExists(dirInfo, filename) Then
                    Return True
                End If

            Next
        Catch e As Exception
            ' This code just writes out the message and continues to recurse.
            ' You may decide to do something different here. For example, you
            ' can try to elevate your privileges and access the file again.
            Console.WriteLine(e.Message)
        End Try

        Return False
    End Function
End Module

Answer 2

You can have an extension on DirectoryInfo that non-recursively iterates through the root directory looking for files.

<Extension()>
Public Iterator Function GetFilesDepthFirst(ByVal root As DirectoryInfo, ByVal Optional dirPattern As String = "*", ByVal Optional filePattern As String = "*.*") As IEnumerable(Of FileInfo)
    Dim stack = New Stack(Of DirectoryInfo)()
    stack.Push(root)

    While stack.Count > 0
        Dim current = stack.Pop()
        Dim files = Enumerable.Empty(Of FileInfo)()
        Dim dirs = Enumerable.Empty(Of DirectoryInfo)()

        Try
            dirs = current.EnumerateDirectories(searchPattern:=dirPattern)
            files = current.EnumerateFiles(searchPattern:=filePattern)
        Catch ex1 As UnauthorizedAccessException
        Catch ex2 As PathTooLongException
        End Try

        For Each file As FileInfo In files
            Yield file
        Next

        For Each dir As DirectoryInfo In dirs
            stack.Push(dir)
        Next
    End While
End Function

You could then call it fairly easily like this:

Dim dInfo = New DirectoryInfo("C:\")
Dim matches = dInfo.GetFilesDepthFirst(filePattern:="somefile.dll")
Dim exists = matches.Any()

Also, the more specific you are at the starting directory, the quicker it will run. Usually searching from the root of C:\ is a very slow and bad idea.