[Tex/LaTex] how to add preface to table of contents

Question

I am trying to add a preface section to the table of contents, by using

  \addcontentsline{toc}{chapter}{Preface}

This partially works. the preface is added, but without the page number for it (in roman letters, it should be, because it is in the frontmatter section).

In addition, the Preface line (which doesn't appear with a page number) is not aligned with the rest of the text for the chapters, since I use chapter* for it, and therefore, there is no number before it.

So it appears as:

      Preface
      1 Introduction

instead of

        Preface
      1 Introduction

When I look into the .toc file, I see:

     \contentsline {chapter}{Preface}{x}{chapter*.1}
     \contentsline {chapter}{\numberline {1}{Introduction}}{1}{chapter.1}

so obviously I can hack it to add a line number, I guess, but I would like to avoid it. I am not sure how to fix the alignment problem, though, through the .toc file (though, again, I wouldn't want to touch the .toc files).

Answer 1

Just a wild guess, but you could use package unnumberedtotoc with option indentunnumbered found in https://tex.stackexchange.com/a/199086/37907.

As you didn't provide any useful code, this is just guesswork.

\documentclass{book}
\usepackage{blindtext}
\usepackage[indentunnumbered]{unnumberedtotoc}

\begin{document}
\tableofcontents

\addchap{Preface}
\blindtext[13]
\chapter{Introduction}
\blindtext[13]
\end{document}