+// this program opens and closes PDF-files with Acrobat or Adobe Reader
+// author: Uwe Stöhr
+
+{The problematic is the following:
+ A PDF-file should be modified while it is opened with Acrobat.
+ This is not possible because Acrobat understands itself as editor, not as
+ reader and therefore opens PDFs always with write access, so that other
+ programs cannot modifiy them.
+ The idea to solve the problem is the following:
+ The file that should be shown in Acrobat is copied and then renamed -
+ the suffix "-preview" is attached. The renamed copy is opened by Acrobat
+ while the unrenamed version can be modified. When the modified version should
+ be displayed, the eventually opened renamed version is closed in Acrobat and
+ the modified version is copied, renamed and opened in Acrobat.}