How to check that I'm compiling using Overleaf?

Question

Is there a simple (boolean) test to check that the document is being compiled on Overleaf (vs elsewhere, i.e. local computer via git download)

Use case (one example) : I'm using fonts that are available only on my laptop and I want Overleaf to fall back to a common font (e.g. free font)

Maybe you could use \IfFileExists to check for the font file — samcarter_is_at_topanswers.xyz, Apr 26 '23 at 12:36
https://tex.stackexchange.com/q/30617/36296 might give you some ideas — samcarter_is_at_topanswers.xyz, Apr 26 '23 at 12:38
If you just want to test whether or not you compile on your own computer, you don't even have to know what the font file is, you could test for any file which overleaf won't have, e.g. ~/My_love_letter_to_TeX.txt in your home folder... — samcarter_is_at_topanswers.xyz, Apr 26 '23 at 12:43
Some other ideas: if you happen to use another operating system than overleaf, you could use the ifplatform package. Overleaf also uses an old texlive version, assuming your system is up to date, you could check the kernel version. — samcarter_is_at_topanswers.xyz, Apr 26 '23 at 12:47
I think testing whether the font file exists should be the way to go, since this is actually the test you are interested in. — Jasper Habicht, Apr 26 '23 at 12:48
Another possible duplicate: https://tex.stackexchange.com/q/596258/36296 — samcarter_is_at_topanswers.xyz, Apr 26 '23 at 12:50

score 3 · Answer 1 · answered Apr 26 '23 at 14:11

Given the usecase mentioned, it seems more prudent to check if the font exists, and if not, to load the fallback font.

To do that, I would recommend the method used in this answer using the fontspec package.

In your case, the MWE from that answer would be changed slightly to:

\documentclass{article}
%\url{https://tex.stackexchange.com/q/438577/86}
\usepackage{fontspec}
% Check to see if this font is installed system-wide
\IfFontExistsTF{TeX Gyre Termes}{%
% One person has this installed system-wide
  \setmainfont{TeX Gyre Termes}
}{
% If not, load it from the file
  \setmainfont{Latin Modern Roman}
}
\begin{document}
Wouldn't it be nice if this were Termes?
\end{document}

replacing TeX Gyre Termes with the font you want to check for and Latin Modern Roman with the font you want to fall back to.

The other possibility is to put the font file into the project directory, assuming you have an .otf or .ttf, and load it using fontspec with \setmainfont{texgyretermes-regular.otf}. This should work on Overleaf as well as locally.

"% Check to see if this font is installed system-wide"
This doesn't work if the font is not already known to the system. i.e local font (say in ./TTFfont/...) and loaded via Path attribute... Am I wrong ? — Val Libre, Apr 27 '23 at 09:18
sorry, I don't quite understand the question. The \IfFontExistsTF command will check if the font you specify is known to your TeX engine, return true/false accordingly. — evamvid, Apr 28 '23 at 09:48
but if you have the font file, I think the most robust way to do this is to put it in the project directory and load it manually. — evamvid, Apr 28 '23 at 09:49

How to check that I'm compiling using Overleaf?

1 Answers1