## Class files

L a T e X is a great tool for printable professional-looking documents, but can be also used to generate PDF files having a navigation-friendly style in mind. In this article is described how to create hyperlinks in your document and how set up the L a T e X document to be browsed in a PDF-reader.

## Introduction

Let's start with a minimal working example, by simply importing the hyperref package all cross-referenced elements become hyperlinked.

\documentclass{book}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage{hyperref}

\begin{document}

\frontmatter

\tableofcontents

...
\end{document}

\usepackage{hyperref}

One must be careful when importing hyperref . Usually it has to be the last package to be imported, but there might be some exceptions to this rule.

## Styles and colours

The default formatting for links can be changed so the information in your documents is more clearly presented. Below you can see an example:

\documentclass{book}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage{hyperref}
\hypersetup{
filecolor=magenta,
urlcolor=cyan,
}

\urlstyle{same}

\begin{document}

\tableofcontents

\chapter{First Chapter}

This will be an empty chapter and I will put some text here

\begin{equation}
\label{eq:1}
\sum_{i=0}^{\infty} a_i x^i
\end{equation}

The equation \ref{eq:1} shows a sum that is divergent. This formula
will be latter used in the page \pageref{second}.

For further references see \href{http://www.sharelatex.com}{Something
Linky} or go to the next url: \url{http://www.sharelatex.com} or open
the next file \href{run:./file.txt}{File.txt}

It's also possible to link directly any word or

If you read this text, you will get noinformation.  Really?  Is there
no information?  Is there a diăŚence between thistext and some nonsense
like Huardest gefburn"?  Kjift { not at all!

For instance \hypertarget{thesentence}{this sentence}.

This is a complete example, it will be fully explained in the rest of the article. Below is a description of the commands related to the colour and styling of the links.

 \hypersetup{ ... } 
This will set the options to configure the behaviour of the links within the document. Every parameter must be comma-separated and the syntax must be in the forma parameter=value .
 \colorlinks=true 
Links will be coloured, the default colour is red.
 \linkcolor=blue 
Internal links, those generated by cross-referenced elements, are displayed in blue.
 \filecolor=magenta 
Links to local files will be shown in magenta colour (see linking local files ).
 \urlcolor=cyan 
 \urlstyle{same} 
Default settings print links in mono-style spaced fonts, this command changes that and displays the links in the same style as the rest of the text.

Links to a web address or email can added to a L a T e X file using the  \url  command to display the actual link or  \href  to use a hidden link and show a word/sentence instead.

For further references see \href{http://www.sharelatex.com}{Something Linky}
or go to the next url: \url{http://www.sharelatex.com}

There are two commands in the example that generate a link in the final document:

 \href{http://www.sharelatex.com}{Something Linky} 
There are two parameters passed to this command, the first one is the url to the link, http://www.sharelatex.com in this case, and the second one is the clickable text to be shown, Something Linky .
 \url{http://www.sharelatex.com} 
This command will show the url passed as parameter and make it into a link, useful if you will print the document.

The commands  \href  and  \url  presented in the previous section can be used to open local files

For further references see \href{http://www.sharelatex.com}{Something Linky}
or go to the next url: \url{http://www.sharelatex.com} or open the next
file \href{run:./file.txt}{File.txt}

The command  \href{run:./file.txt}{File.txt}  prints the text "File.txt" that links to a local file called "file.txt" located in the current working directory. Notice the text "run:" before the path to the file.

The file path follows the conventions of UNIX systems, using . to refer the current directory and .. for the previous directory.

The command  \url{}  can also be used, with the same syntax described for the path, but it's reported to have some problems.

It was mentioned before that all cross-referenced elements become links once hyperref is imported, thus we can use  \label  anywhere in the document and refer later those labels to create links. This is not the only manner to insert hyperlinks manually.

It's also possible to link directly any word
or \hyperlink{thesentence}{any sentence} in you document.

If you read this text, you will get no information.  Really?
Is there no information?

For instance \hypertarget{thesentence}{this sentence}.

There are two commands to create user-defined links.

 \hypertarget{thesentence}{this sentence} 
The first parameter passed inside braces to this command is a unique identifier for this sentence. The second parameter is the text "this sentence", and will be printed normally (depending on the value of anchorcolor , see the reference guide ), but when a link pointing to the identifier "thesentence" is clicked the PDF file will scroll to this point.
 \hyperlink{thesentence}{any sentence} 
This command prints the text "any sentence" as a clickable element that redirects to the point whose identifier is "thesentence".

## PDF-specific options

Links in a document are created having in mind a document that will be read in PDF format. The PDF file can be further personalized to add additional information and change the way the PDF viewer displays it. Below an example:

\hypersetup{
filecolor=magenta,
urlcolor=cyan,
pdftitle={Sharelatex Example},
bookmarks=true,
pdfpagemode=FullScreen,
}

Using the command  \hypersetup  , described in the section styles and colours , accepts extra parameters to set up the final PDF file.

 pdftitle={Sharelatex Example} 
Is the title of the PDF output file, to be displayed in the title bar of the window. In the example is "Sharelatex Example".
 bookmarks=true 
 pdfpagemode=FullScreen 
The document will be opened in full screen mode by the PDF reader.

See the reference guide for a full list of options that can be passed to  \hypersetup  .

## Reference guide

Option Default value Description
 hyperindex  true Makes the page numbers of index entries into hyperlinks
 linktopage  false Makes the page numbers instead of the text to be link in the Table of contents.
 breaklinks  false Allows links to be broken into multiple lines.
 colorlinks  false Colours the text for links and anchors, these colours will appear in the printed version
 linkcolor  red Colour for normal internal links
 anchorcolor  black Colour for anchor (target) text
 citecolor  green Colour for bibliographical citations
 filecolor  cyan Colour for links that open local files
 urlcolor  magenta Colour for linked URLs
 frenchlinks  false Use small caps instead of colours for links

PDF-specific options

Option Default value Description
 bookmarks  true Acrobat bookmarks are written, similar to the table of contents.
 bookmarksopen  false Bookmarks are shown with all sub-trees expanded.
 citebordercolor  0 1 0 Colour of the box around citations in RGB format.
 filebordercolor  0 .5 .5 Colour of the box around links to files in RGB format.
 linkbordercolor  1 0 0 Colour of the box around normal links in RGB format.
 menubordercolor  1 0 0 Colour of the box around menu links in RGB format.
 urlbordercolor  0 1 1 Colour of the box around links to URLs in RGB format.
 pdfpagemode  empty Determines how the file is opened. Possibilities are UseThumbs (Thumbnails), UseOutlines (Bookmarks) and FullScreen.
 pdftitle  Sets the document title.
 pdfauthor  Sets the document Author.
 pdfstartpage  1 Determines on which page the PDF file is opened.