device: works on Windows

Author: scivision

+stdlib/device.m

@@ -1,6 +1,5 @@
 %% DEVICE filesystem device index of path
-% requires: java
-% Windows always returns 0, Unix returns device number.
+% optional: java
 
 function i = device(path)
 arguments
@@ -9,7 +8,30 @@
 
 i = [];
 
-if stdlib.isoctave()
+if ispc()
+  h = NET.addAssembly('System.Management');
+
+  r = stdlib.root_name(path);
+  queryLogicalDisk = sprintf('SELECT VolumeSerialNumber FROM Win32_LogicalDisk WHERE Caption = ''%s''', r);
+
+  % Create a ManagementObjectSearcher instance
+  searcher = System.Management.ManagementObjectSearcher(queryLogicalDisk);
+
+  % Get the collection of ManagementObject instances
+  logicalDisks = searcher.Get();
+
+  % Get the first result (should be at most one for a drive letter)
+  logicalDiskEnumerator = logicalDisks.GetEnumerator();
+  if logicalDiskEnumerator.MoveNext()
+    logicalDisk = logicalDiskEnumerator.Current;
+
+    % Get the VolumeSerialNumber property
+    % This property is a string in WMI, representing a 32-bit hexadecimal integer.
+    i = hex2dec(char(logicalDisk.GetPropertyValue('VolumeSerialNumber')));
+  end
+
+  delete(h)
+elseif stdlib.isoctave()
   [s, err] = stat(path);
   if err == 0
     i = s.dev;

test/TestDisk.m

@@ -49,5 +49,17 @@ function test_filesystem_type(tc, Ps)
 end
 end
 
+
+function test_device(tc)
+
+if ispc()
+  tc.verifyGreaterThan(stdlib.device(pwd()), 0)
+else
+  tc.assumeGreaterThanOrEqual(stdlib.java_api(), 11)
+
+  tc.verifyEqual(stdlib.device("."), stdlib.device(pwd()))
+end
+end
+
 end
 end

test/TestJava.m

@@ -15,13 +15,6 @@ function test_inode(tc)
 end
 
 
-function test_device(tc)
-tc.assumeFalse(ispc(), "not for Windows")
-tc.assumeGreaterThanOrEqual(stdlib.java_api(), 11)
-
-tc.verifyEqual(stdlib.device("."), stdlib.device(pwd()))
-end
-
 function test_owner(tc, Ps)
 
 s = stdlib.get_owner(Ps);