is_{read,write}able: speed

Author: scivision

+stdlib/+legacy/is_readable.m

@@ -3,21 +3,21 @@
 %%% Inputs
 % file: single path string
 %%% Outputs
-% ok: true if file is readable
+% y: true if file is readable
 %
-% the legacy backend is like 40x faster than native
+% this method is like 40x faster than native
 
-function [ok, b] = is_readable(file)
+function y = is_readable(file)
 arguments
-  file string
+  file (1,1) string
 end
 
-if isscalar(file)
-  ok = stdlib.legacy.is_readable(file);
-  b = 'legacy';
+a = stdlib.legacy.file_attributes(file);
+
+if isempty(a)
+  y = false;
 else
-  ok = stdlib.native.is_readable(file);
-  b = 'native';
+  y = a.UserRead || a.GroupRead || a.OtherRead;
 end
 
 end

+stdlib/+legacy/is_writable.m

@@ -3,21 +3,21 @@
 %%% Inputs
 % * file: path to file or folder
 %%% Outputs
-% * ok: true if file is writable
+% * y: true if file is writable
 %
-% the legacy backend is like 40x faster than native
+% this method is like 40x faster than native
 
-function [ok, b] = is_writable(file)
+function y = is_writable(file)
 arguments
-  file string
+  file (1,1) string
 end
 
-if isscalar(file)
-  ok = stdlib.legacy.is_writable(file);
-  b = 'legacy';
+a = stdlib.legacy.file_attributes(file);
+
+if isempty(a)
+  y = false;
 else
-  ok = stdlib.native.is_writable(file);
-  b = 'native';
+  y = a.UserWrite || a.GroupWrite || a.OtherWrite;
 end
 
 end

+stdlib/+native/is_readable.m

@@ -0,0 +1,22 @@
+function y = is_readable(file)
+arguments
+  file (1,1) string
+end
+
+props = "Readable";
+if isunix
+  props = [props, "GroupRead", "OtherRead"];
+end
+
+try
+  y = getPermissions(filePermissions(file), props);
+catch e
+  switch e.identifier
+    case 'MATLAB:io:filesystem:filePermissions:CannotFindLocation'
+      y = logical.empty;
+    otherwise
+      rethrow(e)
+  end
+end
+
+end

+stdlib/+native/is_writable.m

@@ -0,0 +1,23 @@
+function y = is_writable(file)
+arguments
+  file (1,1) string
+end
+
+props = "Writable";
+if isunix
+  props = [props, "GroupWrite", "OtherWrite"];
+end
+
+try
+  y = getPermissions(filePermissions(file), props);
+catch e
+  switch e.identifier
+    case 'MATLAB:io:filesystem:filePermissions:CannotFindLocation'
+      y = logical.empty;
+    otherwise
+      rethrow(e)
+  end
+end
+
+
+end

+stdlib/is_readable.m

@@ -51,30 +51,6 @@ function test_is_char_device(tc, B_is_char_device)
 
 end
 
-
-methods (Test, TestTags={'R2025a'})
-
-function test_is_readable_array(tc)
-tc.assumeFalse(isMATLABReleaseOlderThan('R2025a'))
-in =  [".",  tempname(), mfilename('fullpath') + ".m"];
-out = [true, false,     true];
-
-r = stdlib.is_readable(in);
-tc.verifyEqual(r, out)
-end
-
-
-function test_is_writable_array(tc)
-tc.assumeFalse(isMATLABReleaseOlderThan('R2025a'))
-in =  [".",  tempname(), mfilename('fullpath') + ".m"];
-out = [true, false,     true];
-
-r = stdlib.is_writable(in);
-tc.verifyEqual(r, out)
-end
-
-end
-
 end