VB.net运行过程不起作用-命令行是？

Question

At a command line I can run the folowwing command:

openfiles /query /s \\pha-sr-myserver /v > s:\textfile.txt

This runs fine and produces a list of openfiles on server pha-sr-myserver and outputs it to textfile.txt

Now I am tryng to reproduce this in code, but it's not working:

Dim MyProcess As Process
Dim cText As String
Dim Shellcommand As String = "c:\windows\system32\openfiles.exe"
Dim ShellArgs As String = "/query /s \\pha-sr-myserver /v > S:\textfile.txt"
MyProcess = Process.Start(Shellcommand, ShellArgs)
MyProcess.WaitForExit()

this goes past the stage, but the file is never produced and for the life of me I can not see whats wrong. I've tryed encapsulating the arguments in double quotes etc. I've shelled like this many times but can't seam to get this working. Any ideas would be much apreciated. Thanks Graham

Answer 1

You can try a simple Shell command :

Dim sComando As String
Dim Shellcommand As String = "c:\windows\system32\openfiles.exe"
sComando = """" & Shellcommand & """" & " /query /s \\pha-sr-myserver /v > S:\textfile.txt"
Shell(sComando , AppWinStyle.Normal, True)

or maybe this one:

Dim MyProcess As Process
Dim cText As String
Dim Shellcommand As String = "c:\windows\system32\openfiles.exe"
Dim oShellArgs As ProcessStartInfo


oShellArgs = New ProcessStartInfo(Shellcommand , " /query /s \\pha-sr-myserver /v ")  ' remove this > "  "S:\textfile.txt"" ")
oShellArgs.RedirectStandardOutput = true
oShellArgs.RedirectStandardError = true
MyProcess = Diagnostics.Process.Start(oShellArgs)

MyProcess.StandardOutput.ReadToEnd() ' read this list of string

MyProcess.WaitForExit()

Answer 2

The > S:\\textfile.txt is not understood by openfiles.exe. It is only understood by cmd.exe. You need to either use Process.Start to start cmd.exe or start your app directly and then redirect its standard output to capture it. Try something like this:

Dim shellArgs As String = "/query /s \\pha-sr-myserver /v"
Dim output As String = runCommandLineApp("c:\windows\system32\openfiles.exe", Nothing, shellArgs)
'Do something with output here, such as write it to a file.

Private Function runCommandLineApp(appFileName As String, workingDirectory As String, Optional args As String = Nothing) As String
    Dim psi As New ProcessStartInfo(appFileName, args)
    psi.RedirectStandardOutput = True
    psi.UseShellExecute = False
    psi.CreateNoWindow = True
    psi.WindowStyle = ProcessWindowStyle.Hidden

    If workingFolder IsNot Nothing Then
        psi.WorkingDirectory = workingFolder
    End If

    Dim p As New Process()
    p.StartInfo = psi
    p.Start()

    Dim output As String = p.StandardOutput.ReadToEnd()

    p.WaitForExit()

    Return output

End Function

Answer 3

Only cmd.exe can interpret > as redirection. So, the easiest way is to run cmd.exe from your program.

Dim MyProcess As Process
Dim cText As String
Dim Shellcommand As String = "cmd"
Dim ShellArgs As String = "/c openfiles /query /s \\pha-sr-myserver /v > S:\textfile.txt"
MyProcess = Process.Start(Shellcommand, ShellArgs)
MyProcess.WaitForExit()