How to iterate through the name of files in a folder

Question

Assume I have many TeX files. For the sake of simplicity, also asssume they are in a single folder or directory.

I want to input all files from within my main LaTeX document. Actually I can create a list of those files using C# in advance.

To enrich my view about LaTeX or TeX, could you tell me whether or not this job can be done only by using pure TeX or LaTeX?

---

The following code, that was made by Herbert and adapted by Paulo, has been tested and it works successfully on Windows. A good day!

\documentclass{minimal}
\makeatletter
\def\app@exe{\immediate\write18}
\def\inputAllFiles#1{%
  \app@exe{cmd /c dir /b *.tex > \jobname.tmp}%
  \InputIfFileExists{\jobname.tmp}{}
  \AtEndOfDocument{\app@exe{rm -f #1/\jobname.tmp}}}
\makeatother
\begin{document}

\inputAllFiles{.}% from the current dir 

\end{document}

Answer 1

\documentclass{minimal}
\makeatletter
\def\app@exe{\immediate\write18}
\def\inputAllFiles#1{%
  \app@exe{ls #1/*.txt | xargs cat >> \jobname.tmp}%
  \InputIfFileExists{\jobname.tmp}{}
  \AtEndOfDocument{\app@exe{rm -f #1/\jobname.tmp}}}
\makeatother
\begin{document}

\inputAllFiles{.}% from the current dir 

\end{document}

Not really difficult. It is only an appetizer of how it can be done. This one only reads files *.txt. You have to run it with pdflatex -shell-escape test

Answer 2

A LuaTeX solution:

the TeX driver:

\directlua{dofile("inputall.lua")}

\bye

and the Lua input file inputall.lua:

function dirtree(dir)

  if string.sub(dir, -1) == "/" then
    dir=string.sub(dir, 1, -2)
  end

  local function yieldtree(dir)
    for entry in lfs.dir(dir) do
      if not entry:match("^%.") then
        entry=dir.."/"..entry
          if lfs.isdir(entry) then
            yieldtree(entry)
          else
            coroutine.yield(entry)
          end
      end
    end
  end

  return coroutine.wrap(function() yieldtree(dir) end)
end


for i in dirtree(lfs.currentdir()) do
  local filename = i:gsub(".*/([^/]+)$","%1")
  tex.sprint("\\input " ..  filename .. " ")
end

This recurses down a directory tree and inputs all the file found. (Found the dirtree iterator in the Lua users wiki.)

Answer 3

If there is some sort of naming convention that is used for the files than this can be done as in Can i automatically load chapters and sections based on the filesystem?

\documentclass{article}

\newcommand*{\MaxNumOfChapters}{10}% Adjust these two settings for your needs.
\newcommand*{\MaxNumOfSections}{6}%

\usepackage{pgffor}%

\begin{document}
\foreach \c in {1,2,...,\MaxNumOfChapters}{%
    \foreach \s in {1,2,...,\MaxNumOfSections}{%
        \IfFileExists{Chapter\c/Section\s} {%
            \input{Chapter\c/Section\s}%
        }{%
                % files does not exist, so nothing to do
        }%
    }%
}%
\end{document}

This assumes that there is a directory for each chapter named Chapter<i> directory contains files named Section<n>. Should be able to customize this depending on your specific case.

This should work across different operating systems.

If there is not specfic naming convention, you can adjust this to process a list of files generated by your C# program. For example, if the C# program can generate ListOfFiles.tex as

\newcommand*{\ListOfFiles}{%
    Chapter1/Section1,
    Chapter1/Section2,
    Chapter1/Section3,
    Chapter2/Section1,
    Chapter2/Section2
}%

then you can process this as:

\documentclass{article}%
\usepackage{pgffor}%

\input{ListOfFiles}%

\begin{document}%
\foreach \c in \ListOfFiles {%
    \input{\c}%
}%
\end{document}

Answer 4

I don't know whether you can; you probably can't, and if you could, the facilities for it are almost certainly extremely limited and likely based on \write18, which makes the OS do all the work anyway. However, I don't think you should, since it is far from being a typesetting task, which is the only kind of job TeX is designed to do. Consider:

• If all you want is a list of \input{filename.tex}'s, and if you can already programmatically create a list of filenames using some other language, then you can also generate a TeX file (or file fragment) using that language.

• I don't know how you created these files, but if you did it by hand, then perhaps you gave them meaningful names, like introduction.tex, body.tex, and conclusion.tex. No form of automatic sorting will give you the right order, so you're back to creating a list by some other means, for which see the previous point.

• How many times are you going to TeX this document? If only once, you may as well just write the names in by hand and concentrate on your writing and/or other TeX coding which it contains.

Basically, this is a bookkeeping task which doesn't depend on anything within a TeX document, and therefore is better done by one of the many scripting languages which support filesystem interaction (not to mention programming in general) to a far greater extent than TeX itself.