test:{read,is}_symlink param fun

is_exe: simplify

Author: scivision

+stdlib/+dotnet/read_symlink.m

@@ -0,0 +1,10 @@
+function r = read_symlink(p)
+
+try
+  h = System.IO.FileInfo(p);
+  r = string(h.LinkTarget);
+catch
+  r = string.empty;
+end
+
+end

+stdlib/+java/is_symlink.m

@@ -0,0 +1,5 @@
+function ok = is_symlink(p)
+
+ok = java.nio.file.Files.isSymbolicLink(javaPathObject(stdlib.absolute(p)));
+
+end

+stdlib/+java/read_symlink.m

@@ -0,0 +1,13 @@
+function r = read_symlink(p)
+
+if stdlib.is_symlink(p)
+  % must be absolute path
+  % must not be .canonical or symlink is gobbled!
+  r = stdlib.absolute(p);
+  % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#readSymbolicLink(java.nio.file.Path)
+  r = string(java.nio.file.Files.readSymbolicLink(javaPathObject(r)));
+else
+  r = string.empty;
+end
+
+end

+stdlib/+python/read_symlink.m

@@ -1,5 +1,9 @@
 function r = read_symlink(p)
 
+r = string.empty;
+
+if ~stdlib.is_symlink(p), return, end
+
 % https://docs.python.org/3/library/pathlib.html#pathlib.Path.readlink
 try
   r = string(py.os.readlink(p));
@@ -8,7 +12,6 @@
   end
 catch e
   warning(e.identifier, "read_symlink(%s) failed: %s", p, e.message);
-  r = string.empty;
 end
 
 end

+stdlib/+sys/is_symlink.m

@@ -1,5 +1,9 @@
 function ok = is_symlink(p)
 
+ok = false;
+
+if strlength(p) < 1, return, end
+
 if ispc()
   [s, m] = system(sprintf('pwsh -command "(Get-Item -Path %s).Attributes"', p));
   ok = s == 0 && contains(m, 'ReparsePoint');

+stdlib/+sys/read_symlink.m

@@ -2,6 +2,8 @@
 
 r = string.empty;
 
+if ~stdlib.is_symlink(p), return, end
+
 if isunix()
   cmd = sprintf('readlink -fn %s', p);
 else
@@ -10,7 +12,10 @@
 
 [s, m] = system(cmd);
 if s == 0
-  r = strip(string(m));
+  m = strip(string(m));
+  if strlength(m) > 0
+    r = m;
+  end
 end
 
 end

+stdlib/is_exe.m

@@ -21,8 +21,7 @@
 
 if ~any(i), return, end
 
-
-try
+if ~isMATLABReleaseOlderThan('R2025a')
 
   if isunix
     props = ["UserExecute", "GroupExecute", "OtherExecute"];
@@ -32,16 +31,13 @@
 
   t(i, :) = getPermissions(filePermissions(p(i)), props);
 
-  ok(i) = isfile(p(i)) & any(t{i,:}, 2);
+  ok(i) = any(t{i,:}, 2);
 
-catch e
+else
+
+  a = file_attributes_legacy(p);
+  ok = a.UserExecute || a.GroupExecute || a.OtherExecute;
 
-  switch e.identifier
-    case {'MATLAB:UndefinedFunction', 'Octave:undefined-function'}
-      a = file_attributes_legacy(p);
-      ok = a.UserExecute || a.GroupExecute || a.OtherExecute;
-    otherwise, rethrow(e)
-  end
 end
 
 end

+stdlib/is_symlink.m

@@ -5,33 +5,19 @@
   p {mustBeTextScalar}
 end
 
-if strempty(p)
-  ok = false;
-  return
-end
-
-try
+if ~isMATLABReleaseOlderThan('R2024b')
   ok = isSymbolicLink(p);
-  return
-catch e
-  switch e.identifier
-    case "MATLAB:UndefinedFunction"
-      if stdlib.has_dotnet()
-        ok = stdlib.dotnet.is_symlink(p);
-      elseif stdlib.has_java()
-        ok = java.nio.file.Files.isSymbolicLink(javaPathObject(stdlib.absolute(p)));
-      elseif stdlib.has_python()
-        ok = stdlib.python.is_symlink(p);
-      end
-    case "Octave:undefined-function"
-      % use lstat() to work with a broken symlink, like Matlab isSymbolicLink
-      [s, err] = lstat(p);
-      ok = err == 0 && S_ISLNK(s.mode);
-    otherwise, rethrow(e)
-  end
-end
-
-if ~ok
+elseif stdlib.has_dotnet()
+  ok = stdlib.dotnet.is_symlink(p);
+elseif stdlib.has_java()
+  ok = stdlib.java.is_symlink(p);
+elseif stdlib.has_python()
+  ok = stdlib.python.is_symlink(p);
+elseif stdlib.isoctave()
+  % use lstat() to work with a broken symlink, like Matlab isSymbolicLink
+  [s, err] = lstat(p);
+  ok = err == 0 && S_ISLNK(s.mode);
+else
   ok = stdlib.sys.is_symlink(p);
 end
 

+stdlib/read_symlink.m

@@ -8,36 +8,21 @@
   p {mustBeTextScalar}
 end
 
-r = string.empty;
-
-try
+if ~isMATLABReleaseOlderThan('R2024b')
   [ok, r] = isSymbolicLink(p);
-  if ~ok, r = string.empty; end
-catch e
-  switch e.identifier
-    case "Octave:undefined-function", r = readlink(p);
-    case "MATLAB:UndefinedFunction"
-      if strempty(p) || ~stdlib.is_symlink(p)
-        return
-      end
-
-      if stdlib.dotnet_api() >= 6
-        r = string(System.IO.FileInfo(p).LinkTarget);
-      elseif stdlib.has_java()
-        % must be absolute path
-        % must not be .canonical or symlink is gobbled!
-        r = stdlib.absolute(p);
-        % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#readSymbolicLink(java.nio.file.Path)
-        r = string(java.nio.file.Files.readSymbolicLink(javaPathObject(r)));
-      elseif stdlib.has_python()
-        r = stdlib.python.read_symlink(p);
-      end
-    otherwise, rethrow(e)
-  end
-
-  if strempty(r) && stdlib.exists(r)
-    r = stdlib.sys.read_symlink(p);
+  if ~ok
+    r = string.empty; 
   end
+elseif stdlib.dotnet_api() >= 6
+  r = stdlib.dotnet.read_symlink(p);
+elseif stdlib.has_java()
+  r = stdlib.java.read_symlink(p);
+elseif stdlib.has_python()
+  r = stdlib.python.read_symlink(p);
+elseif stdlib.isoctave()
+  r = readlink(p);
+else
+  r = stdlib.sys.read_symlink(p);
 end
 
 end

test/TestSymlink.m

@@ -10,6 +10,8 @@
 p = {{"not-exist", false}, ...
     {mfilename("fullpath") + ".m", false}, ...
     {"", false}};
+is_symlink_fun   = {@stdlib.is_symlink,   @stdlib.sys.is_symlink,   @stdlib.dotnet.is_symlink,   @stdlib.java.is_symlink,   @stdlib.python.is_symlink}
+read_symlink_fun = {@stdlib.read_symlink, @stdlib.sys.read_symlink, @stdlib.dotnet.read_symlink, @stdlib.java.read_symlink, @stdlib.python.read_symlink}
 end
 
 
@@ -48,22 +50,23 @@ function remove_temp_wd(tc)
 
 methods (Test, TestTags=["impure", "symlink"])
 
-function test_is_symlink(tc, p)
-fprintf("is_symlink  mex: %d\n", stdlib.is_mex_fun("stdlib.is_symlink"))
-tc.verifyTrue(stdlib.is_symlink(tc.link), "failed to detect own link")
-tc.verifyEqual(stdlib.is_symlink(p{1}), p{2}, p{1})
+function test_is_symlink(tc, p, is_symlink_fun)
+is_capable(tc, is_symlink_fun)
+
+tc.verifyTrue(is_symlink_fun(tc.link), "failed to detect own link")
+tc.verifyEqual(is_symlink_fun(p{1}), p{2}, p{1})
 end
 
 
-function test_read_symlink(tc)
-fprintf("read_symlink  mex: %d\n", stdlib.is_mex_fun("stdlib.read_symlink"))
-tc.verifyEmpty(stdlib.read_symlink(""))
-tc.verifyEmpty(stdlib.read_symlink(''))
-tc.verifyEmpty(stdlib.read_symlink(tempname))
-tc.verifyEmpty(stdlib.read_symlink(tc.target))
+function test_read_symlink(tc, read_symlink_fun)
+is_capable(tc, read_symlink_fun)
 
+tc.verifyEmpty(read_symlink_fun(""))
+tc.verifyEmpty(read_symlink_fun(''))
+tc.verifyEmpty(read_symlink_fun(tempname))
+tc.verifyEmpty(read_symlink_fun(tc.target))
 
-link_read = stdlib.read_symlink(tc.link);
+link_read = read_symlink_fun(tc.link);
 
 targ = string(tc.target);
 
@@ -87,4 +90,3 @@ function test_create_symlink(tc)
 
 end
 end
-