I am trying to figure out what process locks a file using the class below. What’s going wrong here?
Call:
private void button1_Click(object sender, EventArgs e)
{
Console.WriteLine(Win32Processes.GetProcessesLockingFile("locked_file.dll").ToString());
}
Output:
System.Collections.Generic.List`1[System.Diagnostics.Process]
Using this call:
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Text;
using System.Threading;
namespace FileLockInfo {
public class Win32Processes {
/// <summary>
/// Return a list of processes that hold on the given file.
/// </summary>
public static List<Process> GetProcessesLockingFile (string filePath) {
var procs = new List<Process>();
foreach (var process in Process.GetProcesses()) {
var files = GetFilesLockedBy(process);
if (files.Contains(filePath)) procs.Add(process);
}
return procs;
}
/// <summary>
/// Return a list of file locks held by the process.
/// </summary>
public static List<string> GetFilesLockedBy (Process process) {
var outp = new List<string>();
ThreadStart ts = delegate {
try {
outp = UnsafeGetFilesLockedBy(process);
} catch {
}
};
try {
var t = new Thread(ts);
t.Start();
if (!t.Join(250)) {
try {
t.Abort();
} catch { }
}
} catch {
}
return outp;
}
#region Inner Workings
private static List<string> UnsafeGetFilesLockedBy (Process process) {
try {
var handles = GetHandles(process);
var files = new List<string>();
foreach (var handle in handles) {
var file = GetFilePath(handle, process);
if (file != null) files.Add(file);
}
return files;
} catch {
return new List<string>();
}
}
const int CNST_SYSTEM_HANDLE_INFORMATION = 16;
const uint STATUS_INFO_LENGTH_MISMATCH = 0xc0000004;
private static string GetFilePath (Win32API.SYSTEM_HANDLE_INFORMATION sYSTEM_HANDLE_INFORMATION, Process process) {
IntPtr m_ipProcessHwnd = Win32API.OpenProcess(Win32API.ProcessAccessFlags.All, false, process.Id);
IntPtr ipHandle = IntPtr.Zero;
var objBasic = new Win32API.OBJECT_BASIC_INFORMATION();
IntPtr ipBasic = IntPtr.Zero;
var objObjectType = new Win32API.OBJECT_TYPE_INFORMATION();
IntPtr ipObjectType = IntPtr.Zero;
var objObjectName = new Win32API.OBJECT_NAME_INFORMATION();
IntPtr ipObjectName = IntPtr.Zero;
string strObjectTypeName = "";
string strObjectName = "";
int nLength = 0;
int nReturn = 0;
IntPtr ipTemp = IntPtr.Zero;
if (!Win32API.DuplicateHandle(m_ipProcessHwnd, sYSTEM_HANDLE_INFORMATION.Handle, Win32API.GetCurrentProcess(), out ipHandle, 0, false, Win32API.DUPLICATE_SAME_ACCESS))
return null;
ipBasic = Marshal.AllocHGlobal(Marshal.SizeOf(objBasic));
Win32API.NtQueryObject(ipHandle, (int)Win32API.ObjectInformationClass.ObjectBasicInformation, ipBasic, Marshal.SizeOf(objBasic), ref nLength);
objBasic = (Win32API.OBJECT_BASIC_INFORMATION)Marshal.PtrToStructure(ipBasic, objBasic.GetType());
Marshal.FreeHGlobal(ipBasic);
ipObjectType = Marshal.AllocHGlobal(objBasic.TypeInformationLength);
nLength = objBasic.TypeInformationLength;
while ((uint)(nReturn = Win32API.NtQueryObject(ipHandle, (int)Win32API.ObjectInformationClass.ObjectTypeInformation, ipObjectType, nLength, ref nLength)) == Win32API.STATUS_INFO_LENGTH_MISMATCH) {
Marshal.FreeHGlobal(ipObjectType);
ipObjectType = Marshal.AllocHGlobal(nLength);
}
objObjectType = (Win32API.OBJECT_TYPE_INFORMATION)Marshal.PtrToStructure(ipObjectType, objObjectType.GetType());
if (Is64Bits()) {
ipTemp = new IntPtr(Convert.ToInt64(objObjectType.Name.Buffer.ToString(), 10) >> 32);
} else {
ipTemp = objObjectType.Name.Buffer;
}
strObjectTypeName = Marshal.PtrToStringUni(ipTemp, objObjectType.Name.Length >> 1);
Marshal.FreeHGlobal(ipObjectType);
if (strObjectTypeName != "File")
return null;
nLength = objBasic.NameInformationLength;
ipObjectName = Marshal.AllocHGlobal(nLength);
while ((uint)(nReturn = Win32API.NtQueryObject(ipHandle, (int)Win32API.ObjectInformationClass.ObjectNameInformation, ipObjectName, nLength, ref nLength)) == Win32API.STATUS_INFO_LENGTH_MISMATCH) {
Marshal.FreeHGlobal(ipObjectName);
ipObjectName = Marshal.AllocHGlobal(nLength);
}
objObjectName = (Win32API.OBJECT_NAME_INFORMATION)Marshal.PtrToStructure(ipObjectName, objObjectName.GetType());
if (Is64Bits()) {
ipTemp = new IntPtr(Convert.ToInt64(objObjectName.Name.Buffer.ToString(), 10) >> 32);
} else {
ipTemp = objObjectName.Name.Buffer;
}
if (ipTemp != IntPtr.Zero) {
byte[] baTemp = new byte[nLength];
try {
Marshal.Copy(ipTemp, baTemp, 0, nLength);
strObjectName = Marshal.PtrToStringUni(Is64Bits() ? new IntPtr(ipTemp.ToInt64()) : new IntPtr(ipTemp.ToInt32()));
} catch (AccessViolationException) {
return null;
} finally {
Marshal.FreeHGlobal(ipObjectName);
Win32API.CloseHandle(ipHandle);
}
}
string path = GetRegularFileNameFromDevice(strObjectName);
try {
return path;
} catch {
return null;
}
}
private static string GetRegularFileNameFromDevice (string strRawName) {
string strFileName = strRawName;
foreach (string strDrivePath in Environment.GetLogicalDrives()) {
StringBuilder sbTargetPath = new StringBuilder(Win32API.MAX_PATH);
if (Win32API.QueryDosDevice(strDrivePath.Substring(0, 2), sbTargetPath, Win32API.MAX_PATH) == 0) {
return strRawName;
}
string strTargetPath = sbTargetPath.ToString();
if (strFileName.StartsWith(strTargetPath)) {
strFileName = strFileName.Replace(strTargetPath, strDrivePath.Substring(0, 2));
break;
}
}
return strFileName;
}
private static List<Win32API.SYSTEM_HANDLE_INFORMATION> GetHandles (Process process) {
uint nStatus;
int nHandleInfoSize = 0x10000;
IntPtr ipHandlePointer = Marshal.AllocHGlobal(nHandleInfoSize);
int nLength = 0;
IntPtr ipHandle = IntPtr.Zero;
while ((nStatus = Win32API.NtQuerySystemInformation(CNST_SYSTEM_HANDLE_INFORMATION, ipHandlePointer, nHandleInfoSize, ref nLength)) == STATUS_INFO_LENGTH_MISMATCH) {
nHandleInfoSize = nLength;
Marshal.FreeHGlobal(ipHandlePointer);
ipHandlePointer = Marshal.AllocHGlobal(nLength);
}
byte[] baTemp = new byte[nLength];
Marshal.Copy(ipHandlePointer, baTemp, 0, nLength);
long lHandleCount = 0;
if (Is64Bits()) {
lHandleCount = Marshal.ReadInt64(ipHandlePointer);
ipHandle = new IntPtr(ipHandlePointer.ToInt64() + 8);
} else {
lHandleCount = Marshal.ReadInt32(ipHandlePointer);
ipHandle = new IntPtr(ipHandlePointer.ToInt32() + 4);
}
Win32API.SYSTEM_HANDLE_INFORMATION shHandle;
List<Win32API.SYSTEM_HANDLE_INFORMATION> lstHandles = new List<Win32API.SYSTEM_HANDLE_INFORMATION>();
for (long lIndex = 0; lIndex < lHandleCount; lIndex++) {
shHandle = new Win32API.SYSTEM_HANDLE_INFORMATION();
if (Is64Bits()) {
shHandle = (Win32API.SYSTEM_HANDLE_INFORMATION)Marshal.PtrToStructure(ipHandle, shHandle.GetType());
ipHandle = new IntPtr(ipHandle.ToInt64() + Marshal.SizeOf(shHandle) + 8);
} else {
ipHandle = new IntPtr(ipHandle.ToInt64() + Marshal.SizeOf(shHandle));
shHandle = (Win32API.SYSTEM_HANDLE_INFORMATION)Marshal.PtrToStructure(ipHandle, shHandle.GetType());
}
if (shHandle.ProcessID != process.Id) continue;
lstHandles.Add(shHandle);
}
return lstHandles;
}
private static bool Is64Bits () {
return Marshal.SizeOf(typeof(IntPtr)) == 8 ? true : false;
}
internal class Win32API {
[DllImport("ntdll.dll")]
public static extern int NtQueryObject (IntPtr ObjectHandle, int
ObjectInformationClass, IntPtr ObjectInformation, int ObjectInformationLength,
ref int returnLength);
[DllImport("kernel32.dll", SetLastError = true)]
public static extern uint QueryDosDevice (string lpDeviceName, StringBuilder lpTargetPath, int ucchMax);
[DllImport("ntdll.dll")]
public static extern uint NtQuerySystemInformation (int
SystemInformationClass, IntPtr SystemInformation, int SystemInformationLength,
ref int returnLength);
[DllImport("kernel32.dll")]
public static extern IntPtr OpenProcess (ProcessAccessFlags dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, int dwProcessId);
[DllImport("kernel32.dll")]
public static extern int CloseHandle (IntPtr hObject);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool DuplicateHandle (IntPtr hSourceProcessHandle,
ushort hSourceHandle, IntPtr hTargetProcessHandle, out IntPtr lpTargetHandle,
uint dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, uint dwOptions);
[DllImport("kernel32.dll")]
public static extern IntPtr GetCurrentProcess ();
public enum ObjectInformationClass : int {
ObjectBasicInformation = 0,
ObjectNameInformation = 1,
ObjectTypeInformation = 2,
ObjectAllTypesInformation = 3,
ObjectHandleInformation = 4
}
[Flags]
public enum ProcessAccessFlags : uint {
All = 0x001F0FFF,
Terminate = 0x00000001,
CreateThread = 0x00000002,
VMOperation = 0x00000008,
VMRead = 0x00000010,
VMWrite = 0x00000020,
DupHandle = 0x00000040,
SetInformation = 0x00000200,
QueryInformation = 0x00000400,
Synchronize = 0x00100000
}
[StructLayout(LayoutKind.Sequential)]
public struct OBJECT_BASIC_INFORMATION { // Information Class 0
public int Attributes;
public int GrantedAccess;
public int HandleCount;
public int PointerCount;
public int PagedPoolUsage;
public int NonPagedPoolUsage;
public int Reserved1;
public int Reserved2;
public int Reserved3;
public int NameInformationLength;
public int TypeInformationLength;
public int SecurityDescriptorLength;
public System.Runtime.InteropServices.ComTypes.FILETIME CreateTime;
}
[StructLayout(LayoutKind.Sequential)]
public struct OBJECT_TYPE_INFORMATION { // Information Class 2
public UNICODE_STRING Name;
public int ObjectCount;
public int HandleCount;
public int Reserved1;
public int Reserved2;
public int Reserved3;
public int Reserved4;
public int PeakObjectCount;
public int PeakHandleCount;
public int Reserved5;
public int Reserved6;
public int Reserved7;
public int Reserved8;
public int InvalidAttributes;
public GENERIC_MAPPING GenericMapping;
public int ValidAccess;
public byte Unknown;
public byte MaintainHandleDatabase;
public int PoolType;
public int PagedPoolUsage;
public int NonPagedPoolUsage;
}
[StructLayout(LayoutKind.Sequential)]
public struct OBJECT_NAME_INFORMATION { // Information Class 1
public UNICODE_STRING Name;
}
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct UNICODE_STRING {
public ushort Length;
public ushort MaximumLength;
public IntPtr Buffer;
}
[StructLayout(LayoutKind.Sequential)]
public struct GENERIC_MAPPING {
public int GenericRead;
public int GenericWrite;
public int GenericExecute;
public int GenericAll;
}
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct SYSTEM_HANDLE_INFORMATION { // Information Class 16
public int ProcessID;
public byte ObjectTypeNumber;
public byte Flags; // 0x01 = PROTECT_FROM_CLOSE, 0x02 = INHERIT
public ushort Handle;
public int Object_Pointer;
public UInt32 GrantedAccess;
}
public const int MAX_PATH = 260;
public const uint STATUS_INFO_LENGTH_MISMATCH = 0xC0000004;
public const int DUPLICATE_SAME_ACCESS = 0x2;
}
#endregion
}
}
You are calling .ToString on a list and that is why you are seeing the output : System.Collections.Generic.List`1[System.Diagnostics.Process].
You need to loop over the returned list from GetProcessesLockingFile and call the ProcessName property of the process object to get the name.
EDIT
ProcessName docs
EXAMPLE