Issue
I got a problem with an API (PHP) I created. The API should create a pdf document depending on the data that is sent. The script works perfectly, running it directly on Ubuntu, Plesk is running on. The part that is not working is the following:
$cmd = sprintf("pdflatex -interaction nonstopmode %s", escapeshellarg(file));
exec($cmd, $foo, $ret);
The tex-file seems not to be touched... no log files or anything. Any ideas about this?
Thank you
Solution
Latex is usually run by experienced users either raw on the command line or via IDE with console interaction, since there is often the need to see from console feedback why a compilation may fail.
The Simplest check for checking is PdfLaTex installed? is at the system console to enter pdflatex --version this should confirm at least a minimal pdflatex has been found in the environment path and show the variant after a rough value for the level of pi.
So in this case responded pdfTeX 3.14159265-2.6-1.40.18 (TeX Live 2017/Debian)
When trying to run unseen it is not easy to get feed back so the smallest test with a small known sample is again at the console to run in a current working directory with batch mode :-
pdflatex -interaction=nonstopmode sample.tex
This should run with little need for checks, however if the paths to pdflatex are not configured you may need to add the location of the pdflatex executable. Thus you discovered needed /usr/bin/pdflatex -interaction=nonstopmode file.tex
There are many different dependencies in LaTeX packages and modules that require the "env" settings be well defined in terms of inter-related paths (e.g. to support files etc.) so it is worth checking those out from the extensive documentation.
Some modules may require elevation to escape shell restrictions via -shell-escape and the above command may need temporary elevation for one run (it should not be needed constantly) so only include when you know exactly from documentation why a module requires it.
It is tempting for TeX novices to think there is an advatage to use sub folder in a working directory for "chapter and verse", since the working directory may "look" cluttered by potentially dozens of runtime files, however much of LaTeX depends on very specific relative pathing and the best way to avoid errors is not need to keep redefining images or other components by variables, simply say it is in the same folder.
Likewise for the packages they should also be set to a fixed location by means of env variables i.e. for bin folder and fonts and other modular supporting components. It is worth reviewing https://tug.org/texlive/quickinstall.html and note the section about minimal path definition but there is much more than that basic setting required by post installed components
Answered By - K J Answer Checked By - Timothy Miller (WPSolving Admin)