XeTeX Unicode – How to Insert Glyphs from an OTF Font?

Question

I'm trying to figure out how to insert specific pictographic glyphs from a font into my document.

So far I have managed to define a new font family using:

\newfontfamily\icons[
    Path = {"/Users/simontoth/Library/Fonts/"},
    Extension = .otf,
    UprightFont = *-Regular-400,
]{Font Awesome 6 Pro}

But when I try to use it with a Unicode glyph number, I run into an error:

! Missing number, treated as zero.
<to be read again>
                   f
l.11 {\icons \symbol{f1f9}
                          }

What am I doing wrong? Or is there a better way to approach this?

Answer 1

The argument of \symbol expects TeX's number syntax. Normally numbers should be given in decimal, but hexadecimal numbers can be used too by adding a " in front of them. In this case, TeX requires them to be given in uppercase. So you need e.g. \symbol{"F1F9} instead of \symbol{f1f9}.