Path to External Files in Nested \input

Question

Problem

I usually load a helping TeX file that contains my customizations, e.g., usual packages, corporate standard colors, and macros for abbreviations. I want my helping file to also load another external file that is in the same folder. I certainly want to avoid giving the explicit path to the second external file every time.

Example

Let's say the helping file is cosmetix.tex, which loads abbreviations.tex. abbreviations.tex is in the same folder as cosmetix.tex and both are in a folder called common:

% cosmetix.tex
% ... some customization
% load abbreviations
\input{abbreviations.tex}

My main file is tester.tex:

% tester.tex
\documentclass{article}

% load cosmetix
\input{common/cosmetix.tex}

\begin{document}
Dummy text.
\end{document}

This leads to the following error: LaTeX error: File `abbreviations.tex' not found.

Question

How can I use nested \inputs with files in different folders without (i) converting my code to a package and (ii) using absolute paths?

Context

Although this question is pretty generic, it is also a follow up to my previous question: Reproducing an official letterhead. I have reproduced my institute's letterhead, which in turn needs to load the logo. I load the letterhead using the \input mechanism. I know this is not the most elegant way, but until I get time to convert this to a package (or read scrlttr2 documentation to convert my letterhead to an option file), this is a solution that reasonably works for me.

As I mentioned above, I can't use absolute paths because I'm using multiple computers with different operating systems, and therefore, the root of the directory tree is different for each computer.

Answer 1

Use the package import, which does exactly one thing: to solve this problem. See

http://www.ctan.org/pkg/import

Basically the package defines two commands: \import and \subimport. \import needs an absolute path, while subimport needs a relative path. They both look at the current folder and TEXINPUTS first. If you want to avoid checking TEXINPUTS, use the starred version.

Example

For your case, the only line you need to change is to update \input to \subimport (and of course, add \usepackage{import}). That is, you would need to write:

\subimport{common}{cosmetix.tex}

No changes are necessary in cosmetix.tex.

Answer 2

I personally try to avoid having to remember to change settings just because I switched computers. And since you are using Dropbox, I would recommend you set up your directory structure so that it is portable and does not require special settings:

 /Projects
     common/
     paper1/
     paper2/

Don't keep files in the \Projetcs directory, but only in the sub-directories, and always use relative paths:

\newcommand*{\CommonPath}{../commom}% 
\input{CommonPath/abbreviations.tex}%

Alternatively, you could adapt one of the solutions from How to detect and condition based on hostname to define a different root path depending on which machine you are on.

Answer 3

As discussed in comments on the question, it seems a reasonable solution is to update the TEXINPUTS variable. You will have to update this variable on all of your computers. If you are using Dropbox or any sync software to keep your computers in sync, you should put the common folder in their path.

For WindEdt/Win7, Choose Variables tab from Options | Execution Modes. Under TEXINPUTS variable (or add it if it's not there) enter the absolute path to the folder. The screen shot below shows how when the common folder is called _Common.

Answer 4

Well I think it is, because input just puts the commands of the file in as is. So the whole file tester.tex would look like

% tester.tex
\documentclass{article}

% load cosmetix
% cosmetix.tex
% ... some customization
% load abbreviations
\input{abbreviations.tex}

\begin{document}
Dummy text.
\end{document}

That will be compiled. Since you are in the folder of tester.tex it cannot load abbreviations.tex. You would need to put \input{common/abbreviations.tex} into cosmetix.tex.