Shell escape after PDF is finished and closed?

Question

I like to escape to the shell using \write18 at the very end of the compilation after the PDF file got completely written and was closed, so that I can use it as part the shell command. Is this somehow possible or does TeX simply closed the PDF at the very last thing? Placing it direct before \end{document} or in \AtEndDocument doesn't help (unsurprisingly). AFAIK \writes are actually whatsit objects and would be normally be part of the document. So I don't have much hopes.

Background

This is used for automatic PDF-to-PNG conversion as a new feature of standalone. At the moment I do this in the preamble in the second run when the old PDF did not yet got opened. This works fine, but I would like to avoid the need to compile standalone diagrams twice.

Answer 1

You do something like this (based on an idea of Ulrich Diez):

\documentclass{article}

\ifx\conditionmacro\undefined
  \immediate\write18{%
    pdfLaTeX --jobname="\jobname"
    \gdef\string\conditionmacro{1}\string\input\space\jobname
  }%
  \immediate\write18{%
    LaTeX --jobname="\jobname"
    \gdef\string\conditionmacro{1}\string\input\space\jobname
  }%
   \immediate\write18{dvips \jobname}
   \expandafter\stop
\fi

\begin{document}
abc
\end{document}

I'm not quite sure if it a very good idea to use \jobname in the subprocesses, it seems to work but \jobname1 or something like this is perhaps safer.

Btw: I'm one of uncool kids who uses windows.

Answer 2

I don't think it's possible; the only place where to hook is \end; let's see an example in LaTeX:

\makeatletter
\let\@@@@end\@@end
\def\@@end{\immediate\write18{ls -l \jobname.pdf}\@@@@end}
\makeatother

\documentclass{article}
\begin{document}
abc
\end{document}

Compiling it gives on standard output

-rw-r--r--  1 staff  159 Jul 13 17:50 shellatend.pdf

but ls -l shellatend.pdf after compilation has ended gives

-rw-r--r--  1 staff  10200 Jul 13 17:50 shellatend.pdf

So the PDF file has not yet been written out completely.

Putting the shell command after \@@@@end does nothing (obviously).

Answer 3

A non-portable solution, which appears to work with TeXLive 2011's pdflatex --shell-escape run in the sh shell (hence most likely any shell based on sh) is to detach the process that you want to run after the end of the pdflatex run. To ensure that things happen after the run has really ended, I used

sleep 3&&\ 
  nohup cp \jobname.pdf \jobname.copy\ 
  2>/dev/null

(without the newline continuations). The first instruction waits 3 seconds for the end of the run (that number is arbitrary), with && detaching it (not sure how that works exactly). Then cp \jobname.pdf \jobname.copy copied the result pdf file; you could replace by the convert utility, or any other actual conversion program. I'm not quite sure why nohup is needed for that but not for the sleep command, but that prevents the call to cp to abort when the parent process (pdflatex) ends. The final step is to redirect errors to 2>/dev/null, because for some reason nohup produces an error (that's probably a bad sign, to investigate).

Of course, to use this in a package for general consumption, you'd need to figure out similar solutions for Windows and Mac, I guess, and figure out whether this covers all other OSes.

\documentclass{article}
\usepackage{lipsum}
\begin{document}

\section{Foo}
\lipsum[1-10]

\section{Bar}
\lipsum[11-20]

\immediate\write18{ls -la \jobname.*}
\immediate\write18
  {sleep 3&&nohup cp "\jobname.pdf" "\jobname.copy" 2>/dev/null&}
\end{document}