diff --git a/plantuml-mode.el b/plantuml-mode.el
index 944ef11..cf5668b 100644
--- a/plantuml-mode.el
+++ b/plantuml-mode.el
@@ -79,16 +79,12 @@
 (defcustom plantuml-suppress-deprecation-warning t
   "To silence the deprecation warning when `puml-mode' is found upon loading.")
 
-(defun plantuml-command-line ()
-  "Compose the PlantUML command line as a string."
-  (mapconcat 'identity (cons plantuml-java-command plantuml-java-args) " "))
-
 (defun plantuml-render-command (&rest arguments)
   "Create a command line to execute PlantUML with arguments (as ARGUMENTS)."
-  (let ((cmd (concat (plantuml-command-line) " " (shell-quote-argument plantuml-jar-path)))
-        (argstring (mapconcat 'identity arguments " ")))
-    (plantuml-debug (format "Command is %s" cmd))
-    (concat cmd " " argstring)))
+  (let* ((cmd-list (append plantuml-java-args (list (expand-file-name plantuml-jar-path)) arguments))
+         (cmd (mapconcat 'identity cmd-list "|")))
+    (plantuml-debug (format "Command is [%s]" cmd))
+    cmd-list))
 
 ;;; syntax table
 (defvar plantuml-mode-syntax-table
@@ -134,11 +130,12 @@
 
 (defun plantuml-init ()
   "Initialize the keywords or builtins from the cmdline language output."
-  (unless (file-exists-p plantuml-jar-path)
+  (unless (or (eq system-type 'cygwin) (file-exists-p plantuml-jar-path))
     (error "Could not find plantuml.jar at %s" plantuml-jar-path))
   (with-temp-buffer
-    (let ((cmd (plantuml-render-command "-charset UTF-8 -language")))
-      (shell-command cmd (current-buffer))
+    (let ((cmd-args (append (list plantuml-java-command nil t nil)
+                            (plantuml-render-command "-charset" "UTF-8" "-language"))))
+      (apply 'call-process cmd-args)
       (goto-char (point-min)))
     (let ((found (search-forward ";" nil t))
           (word "")
@@ -220,7 +217,7 @@ default output type for new buffers."
   `(start-process "PLANTUML" ,buf
                   plantuml-java-command
                   ,@plantuml-java-args
-                  plantuml-jar-path
+                  (expand-file-name plantuml-jar-path)
                   (plantuml-output-type-opt) "-p"))
 
 (defun plantuml-preview-string (prefix string)
@@ -278,6 +275,18 @@ Uses prefix (as PREFIX) to choose where to display it:
                                        (region-beginning) (region-end))
                                       "\n@enduml")))
 
+(defun plantuml-preview-current-block (prefix)
+  "Preview diagram from the PlantUML sources from the previous @startuml to the next @enduml.
+Uses prefix (as PREFIX) to choose where to display it:
+- 4  (when prefixing the command with C-u) -> new window
+- 16 (when prefixing the command with C-u C-u) -> new frame.
+- else -> new buffer"
+  (interactive "p")
+  (save-restriction
+    (narrow-to-region
+     (search-backward "@startuml") (search-forward "@enduml"))
+    (plantuml-preview-buffer prefix)))
+
 (defun plantuml-preview (prefix)
   "Preview diagram from the PlantUML sources.
 Uses the current region if one is active, or the entire buffer otherwise.