READ_SYMLINK read symbolic link

empty string if path is not a symlink

function r = read_symlink(p)
arguments
  p (1,1) string
end

r = "";

try
  [ok, t] = isSymbolicLink(p);
  if ~ok, return, end
catch e
  switch e.identifier
    case "Octave:undefined-function", t = readlink(p);
    case "MATLAB:UndefinedFunction"
      if ~stdlib.is_symlink(p)
        return
      end

      % must be absolute path
      % must not be .canonical or symlink is gobbled!
      r = stdlib.absolute(p, "", false);

      % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#readSymbolicLink(java.nio.file.Path)
      t = java.nio.file.Files.readSymbolicLink(javaPathObject(r));
    otherwise, rethrow(e)
  end
end

r = stdlib.posix(t);

end

%!test
%! if !ispc
%! p = tempname();
%! this = strcat(mfilename("fullpath"), '.m');
%! assert (read_symlink(p), "")
%! assert (create_symlink(this, p))
%! assert (read_symlink(p), this)
%! endif

Published with MATLAB® R2024b