Dos Command in VB

Question

Hi anyone tell me ? can we use DOS Command in VB. If yes than How?

Jaganathan Bantheswaran · Answer

Hi Yes we can use DOS commands. Some of the ways. You can run another application by using the Shell statement. '// this code calls c: est.exe Shell c:	est.exe vbNormalFocus You can also call any program in the windows directory such as regsvr32 notepad and explorer So Shell notepad vbNormalFocus Runs notepad and Shell explorer vbNormalFocus runs explorer. You can also pass any command parameters you need. For example: Shell notepad C:	est.txt vbNormalFocus runs notepad and tells it to open C:	est.txt. Note that if the path you pass contains spaces you need to surround it by quotes: Shell notepad C:\dir with spaces	est.txt vbNormalFocus which is actually the equivalent of passing this: notepad  C:\dir with spaces	est.txt The second parameter specifies the startup position and can be one of the following: Constant - Value - Description vbHide 0 Window is hidden and focus is passed to the hidden window. vbNormalFocus 1 Window has focus and is restored to its original size and position. vbMinimizedFocus 2 Window is displayed as an icon with focus. vbMaximizedFocus 3 Window is maximized with focus. vbNormalNoFocus 4 Window is restored to its most recent size and position. The currently active window remains active. vbMinimizedNoFocus 6 Window is displayed as an icon. The currently active window remains active. The shell function also returns a TaskID (double) that you can use with the AppActivate statement: Private dblNotePadID As Double '// runs word Private Sub cmdRunNotePad_Click() dblNotePadID = Shell(notepad vbNormalFocus) End Sub '// activates word at a later stage Private Sub cmdActivateNotePad_Click() AppActivate dblNotePadID End Sub Option Explicit Private Declare Function ShellExecute Lib shell32.dll Alias ShellExecuteA _ (ByVal hwnd As Long ByVal lpOperation As String ByVal lpFile As String _ ByVal lpParameters As String ByVal lpDirectory As String _ ByVal nShowCmd As Long) As Long Private Const SW_SHOWNORMAL = 1 Private Sub Command1_Click() ShellExecute Me.hwnd vbNullString ExeName.Exe vbNullString C:\ SW_SHOWNORMAL End Sub

Sam Hobbs · Answer

It helps to use accurate terminology. In particular DOS is (as far as I know) not supported in later versions of Windows. You probably mean shell command or command prompt command or console program. If the command is one of the few that the shell (usually cmd.exe) processes then you must do it in a manner such as what Vulpes shows. If not then you don't need to execute cmd.exe. Also note that if the command is one of them that is executed by cmd.exe then there is probably an equivalent .Net class you can use.

Vulpes · Answer

If you're talking here about VB.NET rather than VB6 then you can use the System.Diagnostics.Process class to run the command line interpreter cmd.exe and pass it whatever DOS command you want to run as an argument. For example the following program runs the 'dir' command for the current directory sorting the files by date order - oldest first and redirects the output to a string which is then printed to the console and saved to a file called dir.txt: Imports System Imports System.Diagnostics Imports System.IO Module Program Sub Main() Dim proc As New Process() proc.StartInfo.FileName = cmd.exe proc.StartInfo.Arguments = /C dir /od proc.StartInfo.RedirectStandardOutput = True proc.StartInfo.UseShellExecute = False proc.Start() Dim output As String = proc.StandardOutput.ReadToEnd() proc.WaitForExit() Console.WriteLine(output) File.WriteAllText(dir.txt output) End Sub End Module