sys.is_char_device:windows: heuristic

Author: scivision

+stdlib/+sys/is_char_device.m

@@ -1,8 +1,14 @@
-function y = is_char_device(file)
+function ok = is_char_device(file)
 
-cmd = sprintf('test -c %s', file);
+if ispc()
+  % https://learn.microsoft.com/en-us/windows/console/console-handles
+  charDevs = ["NUL", "CONIN$", "CONOUT$"];
+  ok = any(contains(file, charDevs));
+else
+  cmd = sprintf('test -c %s', file);
 
-[s, ~] = system(cmd);
-y = s == 0;
+  [s, ~] = system(cmd);
+  ok = s == 0;
+end
 
 end

test/TestExists.m

@@ -59,22 +59,14 @@ function test_is_rw_array(tc, backend, fname)
 
 function test_is_char_device(tc, icm)
 % /dev/stdin may not be available on CI systems
-if ispc
-  n = "NUL";
-else
-  n = "/dev/null";
-end
-
-tc.assertNotEmpty(which("stdlib." + icm + ".is_char_device"))
+n = stdlib.null_file();
 
 try
-  y = stdlib.is_char_device(n, icm);
+  tc.verifyTrue(stdlib.is_char_device(n, icm), n)
 catch e
   tc.verifyEqual(e.identifier, 'stdlib:hbackend:NameError', e.message)
-  return
 end
 
-tc.verifyTrue(y)
 end
 
 end

test/TestFileImpure.m

@@ -29,9 +29,11 @@ function test_file_size_array(tc)
 
 
 function test_null_file(tc)
-tc.assumeFalse(ispc)
-
-tc.verifyThat(stdlib.null_file, matlab.unittest.constraints.IsFile)
+if ispc()
+  tc.verifyEqual(stdlib.null_file, "NUL")
+else
+  tc.verifyThat(stdlib.null_file, matlab.unittest.constraints.IsFile)
+end
 end
 
 

test/TestSubprocess.m

@@ -26,8 +26,8 @@ function test_cwd(tc)
   c = 'pwd';
 end
 
-% leave on for debugging.
-cmd_echo = true;
+% true for debugging echo of command.
+cmd_echo = false;
 
 [s, m] = stdlib.subprocess_run(c, 'echo', cmd_echo);
 tc.assertEqual(s, 0, "status non-zero")