How can we parse (extract) latex flie

[prashant]

I have latex file like
\begin{document}

\title{Introduction to \LaTeX{}}
\author{Author’s Name}

\maketitle

How can i extract the title, author etc from latex file. Is any package available or any other best way to do it.

Thanks in advance

[mathew]

You should be aware that LaTeX is a Turing-complete programming language, so in general there won’t be any way to guarantee that you extract particular pieces of metadata. It’s common for people to write custom front page code instead of using the standard \title and \author directives. So your problem is akin to trying to extract metadata from raw Postscript files or HTML pages.

That said, most good LaTeX authors will probably provide metadata in a standard way so that it can be compiled into the PDF. So to solve the problem for those cases, all you really need to do is write some code to scan the file for the appropriate directives and parse the arguments which are in curly brackets. Basically it’s:

\command[optional parameters]{parameters}

You’ll want to implement the hyperref directives, as that package is commonly used when creating indexed PDF documents. Older documents will probably use pdfinfo format. You’ll probably also want to scan for BibTeX metadata in separate sidecar files. Plus, of course, there are the plain LaTeX maketitle directives you already identified.

If by any chance your LaTeX files all use the same formatting package (e.g. they’re all AMS documents), that will obviously make your life a lot easier.

There are also a bunch of programs which can convert LaTeX to plain text for extracting data from the body.