is_{exe,readable,writable} simplify

Author: scivision

+stdlib/get_permissions.m

@@ -13,20 +13,15 @@
   file {mustBeTextScalar}
 end
 
-try
+if stdlib.matlabOlderThan('R2025a')
+  if ~stdlib.exists(file)
+    error('MATLAB:io:filesystem:filePermissions:CannotFindLocation', '%s', file)
+  end
+  perm = perm2char(file_attributes(file));
+  b = 'legacy';
+else
   perm = perm2char(filePermissions(file));
   b = 'native';
-catch e
-  switch e.identifier
-    case {'MATLAB:UndefinedFunction', 'Octave:undefined-function'}
-      perm = perm2char(file_attributes(file));
-      b = 'legacy';
-    case 'MATLAB:io:filesystem:filePermissions:CannotFindLocation'
-      perm = '';
-      b = '';
-    otherwise
-      rethrow(e)
-  end
 end
 
 end

+stdlib/is_exe.m

@@ -16,9 +16,14 @@
 if ispc() && ~has_windows_executable_suffix(file)
   return
 end
+if ~stdlib.exists(file)
+  return
+end
 
-
-try
+if stdlib.matlabOlderThan('R2025a')
+  a = file_attributes(file);
+  y = ~a.directory && (a.UserExecute || a.GroupExecute || a.OtherExecute);
+else
   a = filePermissions(file);
   if a.Type == matlab.io.FileSystemEntryType.File
     if ispc
@@ -27,16 +32,7 @@
       y = a.UserExecute || a.GroupExecute || a.OtherExecute;
     end
   end
-catch e
-  switch e.identifier
-    case 'MATLAB:io:filesystem:filePermissions:CannotFindLocation'
-      y = false;
-    case {'MATLAB:UndefinedFunction', 'Octave:undefined-function'}
-      a = file_attributes(file);
-      y = ~isempty(a) && ~a.directory && (a.UserExecute || a.GroupExecute || a.OtherExecute);
-    otherwise
-      rethrow(e)
-  end
+
 end
 
 end

+stdlib/is_readable.m

@@ -10,18 +10,19 @@
   file {mustBeTextScalar}
 end
 
-try
+if stdlib.matlabOlderThan('R2025a')
+  a = file_attributes(file);
+  if ismissing(a)
+    y = missing;
+  else
+    y = a.UserRead || a.GroupRead || a.OtherRead;
+  end
+else
   a = filePermissions(file);
-  y = a.Readable;
-catch e
-  switch e.identifier
-    case 'MATLAB:io:filesystem:filePermissions:CannotFindLocation'
-      y = false;
-    case {'MATLAB:UndefinedFunction', 'Octave:undefined-function'}
-      a = file_attributes(file);
-      y = ~isempty(a) && (a.UserRead || a.GroupRead || a.OtherRead);
-    otherwise
-      rethrow(e)
+  if ismissing(a)
+    y = missing;
+  else
+    y = a.Readable;
   end
 end
 

+stdlib/is_writable.m

@@ -10,19 +10,12 @@
   file {mustBeTextScalar}
 end
 
-try
+if stdlib.matlabOlderThan('R2025a')
+  a = file_attributes(file);
+  y = a.UserWrite || a.GroupWrite || a.OtherWrite;
+else
   a = filePermissions(file);
   y = a.Writable;
-catch e
-  switch e.identifier
-    case 'MATLAB:io:filesystem:filePermissions:CannotFindLocation'
-      y = false;
-    case {'MATLAB:UndefinedFunction', 'Octave:undefined-function'}
-      a = file_attributes(file);
-      y = ~isempty(a) && (a.UserWrite || a.GroupWrite || a.OtherWrite);
-    otherwise
-      rethrow(e)
-  end
 end
 
 end

+stdlib/private/file_attributes.m

@@ -3,7 +3,7 @@
 [s, r] = fileattrib(file);
 
 if s ~= 1
-  r = struct([]);
+  r = missing;
   return
 end
 

test/TestExists.m

@@ -24,6 +24,10 @@ function test_exists(tc, Ps)
 tc.verifyEqual(r, Ps{2})
 end
 
+function test_not_exists(tc)
+tc.verifyFalse(stdlib.exists(''))
+tc.verifyFalse(stdlib.exists(tempname()))
+end
 
 function test_is_readable(tc, Ps)
 r = stdlib.is_readable(Ps{1});
@@ -33,13 +37,25 @@ function test_is_readable(tc, Ps)
 tc.verifyEqual(r, Ps{2});
 end
 
+function test_is_readable_not_exist(tc)
+e = 'MATLAB:io:filesystem:filePermissions:CannotFindLocation';
+tc.verifyError(@() stdlib.is_readable(''), e)
+tc.verifyError(@() stdlib.is_readable('not-here'), e)
+end
+
 function test_is_writable(tc, Ps)
 r = stdlib.is_writable(Ps{1});
 tc.verifyEqual(r, Ps{2})
 
 r = stdlib.is_writable(string(Ps{1}));
 tc.verifyEqual(r, Ps{2});
 end
+
+function test_is_writable_not_exist(tc)
+e = 'MATLAB:io:filesystem:filePermissions:CannotFindLocation';
+tc.verifyError(@() stdlib.is_writable(''), e)
+tc.verifyError(@() stdlib.is_writable('not-here'), e)
+end
 end
 
 
@@ -68,11 +84,7 @@ function test_is_char_device(tc, B_is_char_device)
 function Ps = init_val()
 
 
-Ps = {
-  {pwd(), true}, ...
-  {tempname(), false}, ...
-  {'', false}
-};
+Ps = {{pwd(), true}};
 
 o = mfilename('fullpath');
 if ~isempty(o)

test/TestPermissions.m

@@ -6,7 +6,8 @@
 end
 
 properties (TestParameter)
-Ps = {'.', pwd(), '', tempname(), 'perm.txt'}
+Ps = {'.', pwd(), 'perm.txt'}
+Pe = {'', tempname()}
 end
 
 
@@ -20,25 +21,28 @@ function w_dirs(tc)
 
 methods (Test, TestTags={'R2016a'})
 
+function test_not_exist(tc, Pe)
+
+e = 'MATLAB:io:filesystem:filePermissions:CannotFindLocation';
+tc.verifyError(@() stdlib.get_permissions(Pe), e)
+
+end
+
 function test_get_permissions(tc, Ps)
 import matlab.unittest.constraints.StartsWithSubstring
 
 [p, b] = stdlib.get_permissions(Ps);
 tc.verifyClass(p, 'char')
 
-if ~stdlib.exists(Ps)
-  tc.verifyEmpty(p)
+if stdlib.matlabOlderThan('R2025a')
+  tc.assertEqual(b, 'legacy')
 else
-  if stdlib.matlabOlderThan('R2025a')
-    tc.assertEqual(b, 'legacy')
-  else
-    tc.assertEqual(b, 'native')
-  end
-
-  tc.verifyThat(p, StartsWithSubstring('r'))
-  if ~ispc() && strcmp(Ps, tc.file)
-    tc.verifyEqual(p(3), '-')
-  end
+  tc.assertEqual(b, 'native')
+end
+
+tc.verifyThat(p, StartsWithSubstring('r'))
+if ~ispc() && strcmp(Ps, tc.file)
+  tc.verifyEqual(p(3), '-')
 end
 end