How to automate introduction of section titles in book

Question

I'm using Spundun's method for automating inputing the entries in a diary, in turn inspired by Peter Grill (Using LaTeX to keep a diary), and I would like to add section dividers by year. This should be easily achieved by introducing an if-then clause with an existential quantifier in it, but I don't know how to do this.

Clarification about directory structure: The directory is of the form /Year/Month/Day.tex (e.g. 2014/Jan/25.tex), and each of the entries starts with \mytitle{Title}. The main .tex file is in the father directory of \Year.

How I think this could be solved: I thought one way to do what I want would be to introduce a clause like the following: for every /year, if there's a file in /Year/Month, input the file /Year.tex —which would include only a line: \section{Year} (say \section{2014}). Unfortunately, I'm not familiar enough with LaTeX to implement the solution.

Here's the code I'm using:

\documentclass{tufte-book}
\usepackage{tikz}
\usepackage{xifthen}

\title{Title}
\author{Author}

\newenvironment{loggentry}[2]%date, heading
{\noindent\textbf{#2}\marginnote{#1}\par}{\vspace{0.5cm}}

\def\?#1{}

\pgfmathtruncatemacro{\StartYear}{2014}
\pgfmathtruncatemacro{\EndYear}{2016}

\newcommand{\writetitle}{0}
\newcommand{\mytitle}[1]
{   \ifthenelse{\writetitle=1}{#1}{}
}

\newread\mysource

\begin{document}
\maketitle

\foreach \Year in {\StartYear,...,\EndYear}
{   \foreach \Month in {Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec}
    {   \foreach \Day in {1,...,31}
    {       \openin\mysource=\Year/\Month/\Day.tex
                \read\mysource to \firstline
                \closein\mysource
                \xdef\writetitle{1}
                \begin{loggentry}{\Year - \Month - \Day}{\firstline}    
                    \xdef\writetitle{0}
                    \input{\Year/\Month/\Day}
                \end{loggentry} 
    }
    {   % files does not exist, so nothing to do
    }

    }  
  }
}

\end{document}

Here's what I would like the result to look like:

Thanks!

Answer 1

A trial of a solution...

I generated dummy directories with year/month/#day.tex files, just a file called #year.tex, i.e. 2014.tex etc. containing the line \section{#year} etc, whereas the #day.tex files contain \mytitle{Some Stuff}\blindtext

In the most inner Foreach loop, I defined \CurrentFileName with the structure as above and use the \LaTeX macro \IfFileExists to be on the safe side, if this is true, then the \openin code from the OP is used.

The OP clearified the question such that there is a 2014.tex etc. in 2014 etc. which contains something like \section{2014}. This should only be included, if there is at least one file in 2014/{Jan,.....,Dec}, otherwise dropped. I tried to achieve this by a status counter variable.

\documentclass{tufte-book}
\usepackage{tikz}
\usepackage{blindtext}%
\usepackage{etoolbox}%


\title{Title}
\author{Author}

\newenvironment{loggentry}[2]%date, heading
{\noindent\textbf{#2}\marginnote{#1}\par}{\vspace{0.5cm}}

\def\?#1{}

\pgfmathtruncatemacro{\StartYear}{2014}
\pgfmathtruncatemacro{\EndYear}{2016}

\newcommand{\writetitle}{0}
\newcommand{\mytitle}[1]
{  
  \ifnumequal{\writetitle}{1}{#1}{}%
}

\newcommand{\InputIfExists}[1]{%
\IfFileExists{#1}{\input{#1}}{}%
}%

\newcounter{includedcntr}
\setcounter{includedcntr}{0}%

\newread\mysource

\begin{document}
\maketitle

\foreach \Year in {\StartYear,...,\EndYear}
{%
  \setcounter{includedcntr}{0}%  Year file is not included so far
  \foreach \Month in {Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec}
  {%   
    \foreach \Day in {1,...,31}
    {% 
      \def\CurrentFileName{\Year/\Month/\Day.tex}%
      \IfFileExists{\CurrentFileName}{%
        %%% Test if any of the expected day files *.tex exists, if true, then
        %%% include the year file and prevent a further inclusion by setting includedcntr to 1
        \ifnumequal{\number\value{includedcntr}}{0}{%
          \InputIfExists{\Year/\Year.tex}%
          \setcounter{includedcntr}{1}}%
        {}%
        % Now read the title
         \openin\mysource=\CurrentFileName%
         \read\mysource to \firstline
         \closein\mysource
         \xdef\writetitle{1}
        \begin{loggentry}{\Year - \Month - \Day}{\firstline}    
          \xdef\writetitle{0}
          \input{\CurrentFileName}\par

        \end{loggentry} 
      }{}%
    }% Day - foreach
  }% Month -foreach
}% Year - foreach

\end{document}%

Here is a small Linux bash script, that generates the files in the local directory:

#!/bin/bash

YEARS="2014 2015 2016"

MONTHS="Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec"

for i in $YEARS
do
 mkdir $i 2> /dev/null
 echo -e "\\\\section{$i}\n" > $i/$i.tex
 for j in $MONTHS
 do
   mkdir -p $i/$j 2> /dev/null
   for k in `seq 1 31` 
   do
     echo -e "\\\\mytitle{Some stuff}\n\\\\blindtext" > $i/$j/$k.tex
   done
 done
done

And here is some of the output