How do I determine a mapped drive's actual path?
I expanded on ibram's answer and created this class (which has been updated per comment feedback). I've probably over documented it, but it should be self-explanatory.
/// <summary>
/// A static class to help with resolving a mapped drive path to a UNC network path.
/// If a local drive path or a UNC network path are passed in, they will just be returned.
/// </summary>
/// <example>
/// using System;
/// using System.IO;
/// using System.Management; // Reference System.Management.dll
///
/// // Example/Test paths, these will need to be adjusted to match your environment.
/// string[] paths = new string[] {
/// @"Z:\ShareName\Sub-Folder",
/// @"\\ACME-FILE\ShareName\Sub-Folder",
/// @"\\ACME.COM\ShareName\Sub-Folder", // DFS
/// @"C:\Temp",
/// @"\\localhost\c$\temp",
/// @"\\workstation\Temp",
/// @"Z:", // Mapped drive pointing to \\workstation\Temp
/// @"C:\",
/// @"Temp",
/// @".\Temp",
/// @"..\Temp",
/// "",
/// " ",
/// null
/// };
///
/// foreach (var curPath in paths) {
/// try {
/// Console.WriteLine(string.Format("{0} = {1}",
/// curPath,
/// MappedDriveResolver.ResolveToUNC(curPath))
/// );
/// }
/// catch (Exception ex) {
/// Console.WriteLine(string.Format("{0} = {1}",
/// curPath,
/// ex.Message)
/// );
/// }
/// }
/// </example>
public static class MappedDriveResolver
{
/// <summary>
/// Resolves the given path to a full UNC path if the path is a mapped drive.
/// Otherwise, just returns the given path.
/// </summary>
/// <param name="path">The path to resolve.</param>
/// <returns></returns>
public static string ResolveToUNC(string path) {
if (String.IsNullOrWhiteSpace(path)) {
throw new ArgumentNullException("The path argument was null or whitespace.");
}
if (!Path.IsPathRooted(path)) {
throw new ArgumentException(
string.Format("The path '{0}' was not a rooted path and ResolveToUNC does not support relative paths.",
path)
);
}
// Is the path already in the UNC format?
if (path.StartsWith(@"\\")) {
return path;
}
string rootPath = ResolveToRootUNC(path);
if (path.StartsWith(rootPath)) {
return path; // Local drive, no resolving occurred
}
else {
return path.Replace(GetDriveLetter(path), rootPath);
}
}
/// <summary>
/// Resolves the given path to a root UNC path if the path is a mapped drive.
/// Otherwise, just returns the given path.
/// </summary>
/// <param name="path">The path to resolve.</param>
/// <returns></returns>
public static string ResolveToRootUNC(string path) {
if (String.IsNullOrWhiteSpace(path)) {
throw new ArgumentNullException("The path argument was null or whitespace.");
}
if (!Path.IsPathRooted(path)) {
throw new ArgumentException(
string.Format("The path '{0}' was not a rooted path and ResolveToRootUNC does not support relative paths.",
path)
);
}
if (path.StartsWith(@"\\")) {
return Directory.GetDirectoryRoot(path);
}
// Get just the drive letter for WMI call
string driveletter = GetDriveLetter(path);
// Query WMI if the drive letter is a network drive, and if so the UNC path for it
using (ManagementObject mo = new ManagementObject()) {
mo.Path = new ManagementPath(string.Format("Win32_LogicalDisk='{0}'", driveletter));
DriveType driveType = (DriveType)((uint)mo["DriveType"]);
string networkRoot = Convert.ToString(mo["ProviderName"]);
if (driveType == DriveType.Network) {
return networkRoot;
}
else {
return driveletter + Path.DirectorySeparatorChar;
}
}
}
/// <summary>
/// Checks if the given path is a network drive.
/// </summary>
/// <param name="path">The path to check.</param>
/// <returns></returns>
public static bool isNetworkDrive(string path) {
if (String.IsNullOrWhiteSpace(path)) {
throw new ArgumentNullException("The path argument was null or whitespace.");
}
if (!Path.IsPathRooted(path)) {
throw new ArgumentException(
string.Format("The path '{0}' was not a rooted path and ResolveToRootUNC does not support relative paths.",
path)
);
}
if (path.StartsWith(@"\\")) {
return true;
}
// Get just the drive letter for WMI call
string driveletter = GetDriveLetter(path);
// Query WMI if the drive letter is a network drive
using (ManagementObject mo = new ManagementObject()) {
mo.Path = new ManagementPath(string.Format("Win32_LogicalDisk='{0}'", driveletter));
DriveType driveType = (DriveType)((uint)mo["DriveType"]);
return driveType == DriveType.Network;
}
}
/// <summary>
/// Given a path will extract just the drive letter with volume separator.
/// </summary>
/// <param name="path"></param>
/// <returns>C:</returns>
public static string GetDriveLetter(string path) {
if (String.IsNullOrWhiteSpace(path)) {
throw new ArgumentNullException("The path argument was null or whitespace.");
}
if (!Path.IsPathRooted(path)) {
throw new ArgumentException(
string.Format("The path '{0}' was not a rooted path and GetDriveLetter does not support relative paths.",
path)
);
}
if (path.StartsWith(@"\\")) {
throw new ArgumentException("A UNC path was passed to GetDriveLetter");
}
return Directory.GetDirectoryRoot(path).Replace(Path.DirectorySeparatorChar.ToString(), "");
}
}
I can't remember where I found this, but it works without p/invoke. It's what rerun posted before.
you need to reference System.Management.dll:
using System.IO;
using System.Management;
code:
public void FindUNCPaths()
{
DriveInfo[] dis = DriveInfo.GetDrives();
foreach( DriveInfo di in dis )
{
if(di.DriveType == DriveType.Network)
{
DirectoryInfo dir = di.RootDirectory;
// "x:"
MessageBox.Show( GetUNCPath( dir.FullName.Substring( 0, 2 ) ) );
}
}
}
public string GetUNCPath(string path)
{
if(path.StartsWith(@"\\"))
{
return path;
}
ManagementObject mo = new ManagementObject();
mo.Path = new ManagementPath( String.Format( "Win32_LogicalDisk='{0}'", path ) );
// DriveType 4 = Network Drive
if(Convert.ToUInt32(mo["DriveType"]) == 4 )
{
return Convert.ToString(mo["ProviderName"]);
}
else
{
return path;
}
}
Update: Explicitly running as administrator will not show mapped drives. Here is an explanation of this behaviour: https://stackoverflow.com/a/11268410/448100 (in short: administrator has a different user context, so no access to mapped drives of normal user)
Here are some code samples:
- Using P/Invoke
All of the magic derives from a Windows function:
[DllImport("mpr.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern int WNetGetConnection(
[MarshalAs(UnmanagedType.LPTStr)] string localName,
[MarshalAs(UnmanagedType.LPTStr)] StringBuilder remoteName,
ref int length);
Example invocation:
var sb = new StringBuilder(512);
var size = sb.Capacity;
var error = Mpr.WNetGetConnection("Z:", sb, ref size);
if (error != 0)
throw new Win32Exception(error, "WNetGetConnection failed");
var networkpath = sb.ToString();