I'm trying to use arabic script but it seems I run into trouble, the output is just a mess of question marks, literally. I took this code from this page
(I'm on Macbook Pro Yosemite, TeXLive, TeXshop, XeLaTeX etc)
\documentclass{book}
\usepackage{setspace}
\usepackage{fontspec}
\usepackage{polyglossia}
\setmainlanguage{english}
\setotherlanguage{arabic}
\newfontfamily\arabicfont[Script=Arabic,Scale=1.1]{Scheherazade}
\begin{document}
Some latin text and inline arabic: \textarabic{السلام عليكم}
And for larger blocks of text you can use Arabic environment:
\begin{Arabic}
العربية أكثر لغات المجمأعلى الصفحة إلى أسفلها.
\end{Arabic}
To get even spacing between lines, you can use \verb|\lineskiplimit| command (locally or globally, preferably locally) and set spacing with \verb|setspace| or \verb|leading| package to avoid possible overlapping:
\begin{Arabic}
\lineskiplimit=-1000pt
\setstretch{1.2}
العربية أكثر لغات المجموعة السامية متحدثينَ، وإحدى أكثر اللغات انتشارًا في العافارسية والعبرية وعلى عكس الكثير من اللغات العالمية - ومن أعلى الصفحة إلى أسفلها.
\end{Arabic}
\end{document}
The output is

To the best of my knowledge, I have installed the Scherzade font (I see it in other softwares/Pages) but I'm not so sure about the Polyglossia thing. Anyone know how I can fix this?
% !TEX encoding = UTF-8 Unicodeat the beginning of your file. And if you want to use this encoding as a default for all your subsequent files, you can either use this line systematically (e.g. via a template) or open TeXShop's Preferences, its Document panel, and there select “Unicode (UTF-8)” in the “Encoding” section. – Franck Pastor Apr 20 '15 at 14:24