Get platform-specific Ghostscript executable name

scripts/pdf_unlock.py

@@ -56,8 +56,14 @@ def pdf_unlock(pdf_file, overwrite=False):
     if input_name.endswith(suffix):
         return
 
-    # save as temporary file
-    cmd_str = ('gs '
+    # Get name of Ghostscript executable
+    if os.sys.platform == 'win32':
+        exec_name = 'gswin64c'
+    else:
+        exec_name = 'gs'
+
+    # Create Ghostscript command string
+    cmd_str = ('{} '
                '-dSAFER '
                '-dNOPAUSE '
                '-dQUIET '
@@ -65,7 +71,7 @@ def pdf_unlock(pdf_file, overwrite=False):
                '-sPDFPassword= '
                '-sDEVICE=pdfwrite '
                '-sOutputFile="{}.pdf" '
-               '"{}.pdf"').format(output_name, input_name)
+               '"{}.pdf"').format(exec_name, output_name, input_name)
 
     with subprocess.Popen(
             cmd_str, stdout=subprocess.PIPE, bufsize=1,