avoiding escaping in Bash here documents

Question

How can I store text in a Bash here document without having to escape special characters? For example, how could I modify the following script in order to preserve the LaTeX code?:

#!/bin/bash

IFS= read -d '' titlePage << "EOF"
\documentclass{article}
\usepackage{graphicx}
\usepackage{fix-cm}
\begin{document}
\pagestyle{empty}
\vspace*{\fill}
\begin{center}
\hrule
\vspace{1.5 cm}
\textbf{
\fontsize{25}{45}\selectfont
The Title\\
of\\
\fontsize{45}{45}\selectfont
\vspace{0.5 cm}
THIS DOCUMENT\\
\vspace{1.5 cm}
\hrule
\vspace{3.5 cm}
}
\end{center}
\vspace*{\fill}
\end{document}
EOF
echo "${titlePage}" >> 0.tex
pdflatex 0.tex

Answer 1

The problem is not with the here doc, but with the fact that read parses its input. Using read -r should help; or if you really just want the here doc in a file, cat <<'here' >file

Answer 2

Disclaimer:

• See @tripleee's answer for the correct and simplest solution.
• While this answer always worked, it originally contained an incorrect claim. Now it's just an alternative solution.

Since a variable is being assigned to here, another solution is to use a regular - but multiline - single-quoted string literal:

titlePage='\documentclass{article}
\usepackage{graphicx}
\usepackage{fix-cm}
\begin{document}
\pagestyle{empty}
\vspace*{\fill}
\begin{center}
\hrule
\vspace{1.5 cm}
\textbf{
\fontsize{25}{45}\selectfont
The Title\\
of\\
\fontsize{45}{45}\selectfont
\vspace{0.5 cm}
THIS DOCUMENT\\
\vspace{1.5 cm}
\hrule
\vspace{3.5 cm}
}
\end{center}
\vspace*{\fill}
\end{document}'

echo "${titlePage}" >> 0.tex
pdflatex 0.tex

Whitespace matters inside the string:

• The content starts right after the opening '.
• Ends by placing the closing ' directly after the last char. - unless you want a terminating \n.
• The - here-doc option to strip leading tabs (so as to allow indentation for visual clarity) is NOT available with this approach.

Answer 3

For stuff like that, you can also consider sedding it out of the file itself. It also separates your code from the data. (That's why I often use it.)

#!/bin/sh

titlepage=$(sed '1,/^#START-TITLE/d;/^#END-TITLE/,$d' $0)
....
exit 0

#START-TITLE
.....
#END-TITLE

Also consider an indented here doc:

foo <<- \marker
    tab-indented text
    marker

that also gives (some) visual separation.