shell fallback is_symlink

Author: scivision

+stdlib/+sys/is_symlink.m

@@ -0,0 +1,11 @@
+function ok = is_symlink(p)
+
+if ispc()
+  [s, m] = system(sprintf('pwsh -command "(Get-Item -Path %s).Attributes"', p));
+  ok = s == 0 && contains(m, 'ReparsePoint');
+else
+  [s, ~] = system(sprintf('test -L %s', p));
+  ok = s == 0;
+end
+
+end

+stdlib/is_symlink.m

@@ -5,8 +5,14 @@
   p {mustBeTextScalar}
 end
 
+if strempty(p)
+  ok = false;
+  return
+end
+
 try
   ok = isSymbolicLink(p);
+  return
 catch e
   switch e.identifier
     case "MATLAB:UndefinedFunction"
@@ -16,11 +22,6 @@
         ok = java.nio.file.Files.isSymbolicLink(javaPathObject(stdlib.absolute(p)));
       elseif stdlib.has_python()
         ok = stdlib.python.is_symlink(p);
-      elseif isunix()
-        ok = system(sprintf('test -L %s', p)) == 0;
-      elseif ispc()
-        [s, m] = system(sprintf('pwsh -command "(Get-Item -Path %s).Attributes"', p));
-        ok = s == 0 && contains(m, 'ReparsePoint');
       end
     case "Octave:undefined-function"
       % use lstat() to work with a broken symlink, like Matlab isSymbolicLink
@@ -30,6 +31,10 @@
   end
 end
 
+if ~ok
+  ok = stdlib.sys.is_symlink(p);
+end
+
 end
 
 

test/TestSymlink.m

@@ -7,7 +7,9 @@
 end
 
 properties (TestParameter)
-p = init_symlink()
+p = {{"not-exist", false}, ...
+    {mfilename("fullpath") + ".m", false}, ...
+    {"", false}};
 end
 
 
@@ -86,9 +88,3 @@ function test_create_symlink(tc)
 end
 end
 
-
-function p = init_symlink()
-p = {{"not-exist", false}, ...
-  {mfilename("fullpath") + ".m", false}, ...
-  {"", false}};
-end