How to find the path of external process?

[gecka]

Hi to all!

I want to get the directory a program was launched from. These processes aren't started in my code, they are started using the usual windows explorer.
I checked System.Diagnostics.Process and it doesn't seem it has that functionality.

Any help appreciated!

[Zaccheus]

How would you identify the process you are looking for?

For example, if you know the process id, then you can create a Process object using System.Diagnostics.Process.GetProcessById. Or you can find all processes, using System.Diagnostics.Process.GetProcesses.

Each process object has a MainModule property from which you can get the full pathname.

[StarShaper]

Use this:

    using System.Runtime.InteropServices;   // For P/Invoke

...

public class ModFilePath
    {
        [DllImport("kernel32.dll", SetLastError = true)]
        [System.Security.SuppressUnmanagedCodeSecurity]
 
        // DWORD GetModuleFileName(
        //   HMODULE hModule,
        //   LPTSTR lpFilename,
        //   DWORD nSize
        // );        
        private static extern uint GetModuleFileName(
            [In] IntPtr hModule,
            [Out] StringBuilder lpFilename,
            [In] [MarshalAs (UnmanagedType.U4)] int nSize);
 
        public string StartupPath
        {
            get
            {
                StringBuilder sb = new StringBuilder(260);
 
                if (GetModuleFileName(IntPtr.Zero, sb, sb.Capacity) == 0)
                {
                    throw new ApplicationException("Could not retrive module file path!");
                }
 
                return Path.GetDirectoryName(sb.ToString());
            }
        }
    }

Call with ModFilePath filepath = new ModFilePath(); and string localFileName = filepath.StartupPath

[Zaccheus]

You don't need to use GetModuleFileName via p/invoke, you can get full pathname from the Process class' MainModule property.

[gecka]

Thank you for your help!

About process identifying, I think there's no other way to do this, but use process' name. And that's why I needed path to the exe, to check if the program was launched from directory I need.

[Zaccheus]

In that case, I think you can just call System.Diagnostics.Process.GetProcesses and itereate through the returned array.