B4J Question Is it possible to get all pids of system?

[liulifeng77]

hi,
in app A, I want to get all pids and check app B is or not running,if not, restart app B.

thanks!

 

[sorex]

not sure if there is a direct method but you can always do a "tasklist >tasks.txt" via a shell command and parse the text file.

 

[NJDude]

As Sorex mentioned above you will have to do via a shell command, for example with PowerShell, the following example will start the Calculator if it's not running.

If (-Not(Get-Process Calc)) {

    Start-Process Calc

}

One Liner:

Powershell.exe If (-Not(Get-Process Calc)) { Start-Process Calc }

 

[OliverA]

1) Download jna and jna-platform jars from https://github.com/java-native-access/jna and place into additional libraries folder.
2) Adapt the code from a stackoverflow post (https://stackoverflow.com/a/13478508).
3) Tada

'Non-UI application (console / server application)
#Region Project Attributes
   #CommandLineArgs:
   #MergeLibraries: True
#End Region

#AdditionalJar: jna-4.5.1
#AdditionalJar: jna-platform-4.5.1

Sub Process_Globals
   
End Sub

Sub AppStart (Args() As String)
   Dim processList As List = ListWinProcesses
   For Each item As String In processList
       Log(item)
   Next
   
   Dim processPIDs As List = ListWinProcessPIDs("firefox.exe")
   For Each item2 As Int In processPIDs
       Log(item2)
   Next
End Sub

'Produce a list Windows PID's and the associated EXE file
Sub ListWinProcesses() As List
   Dim joMe As JavaObject = Me
   Return joMe.RunMethod("listWinProcesses", Null)
End Sub

'For a given Windows EXE file, produce a list of PID's. EXE filename will be
' treated as case insensitive.
Sub ListWinProcessPIDs(process As String) As List
   Dim joMe As JavaObject = Me
   Return joMe.RunMethod("listWinProcessPIDs", Array As Object(process))
End Sub

'Return true to allow the default exceptions handler to handle the uncaught exception.
Sub Application_Error (Error As Exception, StackTrace As String) As Boolean
   Return True
End Sub

#if Java
//Adapted from: https://stackoverflow.com/a/13478508
import com.sun.jna.platform.win32.Kernel32;
import com.sun.jna.platform.win32.Tlhelp32;
import com.sun.jna.platform.win32.WinDef;
import com.sun.jna.platform.win32.WinNT;
import com.sun.jna.win32.W32APIOptions;
import com.sun.jna.Native;

import java.util.ArrayList;
import java.util.List;

static public List listWinProcesses() {
   List<String>listOfProcesses = new ArrayList<String>();
   
   Kernel32 kernel32 = (Kernel32) Native.loadLibrary(Kernel32.class, W32APIOptions.UNICODE_OPTIONS);
   Tlhelp32.PROCESSENTRY32.ByReference processEntry = new Tlhelp32.PROCESSENTRY32.ByReference();         
   WinNT.HANDLE snapshot = kernel32.CreateToolhelp32Snapshot(Tlhelp32.TH32CS_SNAPPROCESS, new WinDef.DWORD(0));
   try  {
       while (kernel32.Process32Next(snapshot, processEntry)) {             
           listOfProcesses.add(processEntry.th32ProcessID + "\t" + Native.toString(processEntry.szExeFile));
       }
   }
   finally {
       kernel32.CloseHandle(snapshot);
   }
   
   return listOfProcesses;
}

// Note: parameter process will be treated as case insensitive
static public List listWinProcessPIDs(String process) {
   List<Integer>listOfPIDs = new ArrayList<Integer>();
   
   Kernel32 kernel32 = (Kernel32) Native.loadLibrary(Kernel32.class, W32APIOptions.UNICODE_OPTIONS);
   Tlhelp32.PROCESSENTRY32.ByReference processEntry = new Tlhelp32.PROCESSENTRY32.ByReference();         
   WinNT.HANDLE snapshot = kernel32.CreateToolhelp32Snapshot(Tlhelp32.TH32CS_SNAPPROCESS, new WinDef.DWORD(0));
   try  {
       while (kernel32.Process32Next(snapshot, processEntry)) {
           if(Native.toString(processEntry.szExeFile).equalsIgnoreCase(process)) {
               listOfPIDs.add(Integer.parseInt(processEntry.th32ProcessID + ""));
           }
       }
   }
   finally {
       kernel32.CloseHandle(snapshot);
   }
   
   return listOfPIDs;   
}
#End If

Note: In the inline Jave, remove the static qualifier on the methods when not used in Main.

 

[liulifeng77]

thanks all!