How I can automatically add a page if the total number of pages is odd?

Question

I need automatically add a blank page (also without document header, numbering and footer) at the end of the document, if the total numbers of pages is odd. How I can do that? And preferably without using any additional package. :)

Answer 1

Like this?

\documentclass[twoside]{article}

\begin{document}

one
\cleardoublepage
\end{document} 

Or you could use this version

\makeatletter

\def\emptycleardoublepage{\clearpage\if@twoside \ifodd\c@page\else
\thispagestyle{empty}%
\hbox{}\newpage\if@twocolumn\hbox{}\newpage\fi\fi\fi}

\makeatother

which is the same as the standard \cleardoublepage except for the \thispagestyle{empty}% of course you don't just have to use empty you can have page style that inserts this page intentionally blank or whatever else is needed.

Answer 2

Here's one possible option: with the help of the lastpage package, you can check if the last page is odd or even; in the first case, add an extra page with empty style; otherwise, do nothing:

\documentclass{article}
\usepackage{ifthen}
\usepackage{lastpage}
\usepackage{lipsum}

\AtEndDocument{%
  \ifthenelse{\isodd{\pageref{LastPage}}}{\null\clearpage\thispagestyle{empty}}{}}

\begin{document}

\lipsum[1]

\end{document}

Actually, a refinement is needed to satisfy the condition for the added page (empty page style):

\documentclass{article}
\usepackage{ifthen}
\usepackage{lastpage}
\usepackage{lipsum}


\makeatletter
\def\emptyclearpage{%
  \ifvmode
    \ifnum \@dbltopnum =\m@ne
      \ifdim \pagetotal <\topskip
        \hbox{}%
      \fi
    \fi
  \fi
  \newpage\thispagestyle{empty}
  \write\m@ne{}%
  \vbox{}%
  \penalty -\@Mi
}
\makeatother

\AtEndDocument{%
  \emptyclearpage
  \ifthenelse{\isodd{\pageref{LastPage}}}{\null\emptyclearpage}{}}

\begin{document}

\lipsum[1]

\end{document}

Answer 3

Original answer to Ensure last page is even and blank (now merged with this question.)

---

If you want to ensure even number of pages in twoside mode you can simply add \cleardoublepage at the end of the document, either manually or using \AtEndDocument{..}. If you want to have the page blank you need to modify the code used by \cleardoublepage slightly to include a \thispagestyle:

\documentclass[twoside]{report}

%\AtEndDocument{\cleardoublepage}
\AtEndDocument{% based in \cleardoublepage
  \clearpage
  \ifodd\value{page}\else
    \thispagestyle{empty}%
    \hbox{}\newpage
  \fi
}

\usepackage{lipsum}% for dummy text
\begin{document}

\lipsum[1-47]

\end{document}

This is for twoside document only. See my answer to How to force output to a left (or right) page? for the extra code needed to behave well in oneside documents as well.

Answer 4

You can use \AtEndDocument to add an empty page to the end of the document if the text ends on an even page.

\documentclass{article}
\AtEndDocument{ \ifodd\value{page}\else\newpage\thispagestyle{empty} \hbox{} \fi }
\begin{document}
A \newpage B \newpage C \newpage D
\end{document}