# Using bibtool with biblatex

I'm trying to use bibtool to extract bibliography information from an aux file. I'm using this MWE:

\documentclass[12pt]{article}
\usepackage{filecontents}
\begin{filecontents}{foo.bib}
@Book{dickens,
author={Charles Dickens},
title={A Tale of Two Cities},
year=1859,
publisher={Chapman and Hall}
}
\end{filecontents}
\usepackage[style=verbose]{biblatex}
\bibliography{foo}

\begin{document}
\cite{dickens}

\end{document}


When I run:

bibtool -x test.aux -o refs.bib


I get the following errors:

*** BibTool WARNING:  (line 2 in ./test-blx.bib): 23 non-space characters ignored.

*** BibTool WARNING:  (line 9 in ./test-blx.bib): 168 non-space characters ignored.

@Control{biblatex-control,
_^
*** BibTool ERROR:  (line 9 in ./test-blx.bib): Unknown entry type

*** BibTool WARNING: Skiping to next '@'

*** BibTool WARNING:  (line 5 in ./foo.bib): 96 non-space characters ignored.


My test.aux is as follows:

\relax
\bibstyle{biblatex}
\bibdata{test-blx,foo}
\citation{biblatex-control}
\citation{dickens}
\@writefile{toc}{\boolfalse {citerequest}\boolfalse {citetracker}\boolfalse {pagetracker}\boolfalse {backtracker}\relax }
\@writefile{lof}{\boolfalse {citerequest}\boolfalse {citetracker}\boolfalse {pagetracker}\boolfalse {backtracker}\relax }
\@writefile{lot}{\boolfalse {citerequest}\boolfalse {citetracker}\boolfalse {pagetracker}\boolfalse {backtracker}\relax }
\abx@aux@page{1}{1}


I presume this problem is because this tool has been written for bibtex rather than biblatex. Is there a way to use this tool to extract the information, or is there a way to extract the bibliography information I need?

-
In case you are using biber to generate the bibliography, you might want to checkout the --output-format=bibtex commandline option as described in its manual. –  michel Nov 14 '13 at 19:51

I found an answer to this. Change \bibstyle to plain in your .aux file, and delete the \citation{biblatex-control} line. bibtool should now be able to read your bibliography as per usual. (You might also want to remove test-blx.bib from the \bibdata thing, I can't remember if it works without that)