How can I produce the old glyph "long s" in Latex?

Question

In old texts, one finds the glyph "long s", that I was not able to find a proper Latex representation: https://en.wikipedia.org/wiki/Long_s

How can I produce "long s" in Latex?

I am aware of How to enable old ligatures, long s in LaTeX? but this was not helpful in solving the problem.

Answer 1

Computer Modern Unicode does have the glyph, as well as a few other fonts, e.g. erewhon, libertinus, &c. However, I found only ebgaramond that worked – yet it doesn't make the difference with the final s (I added a spelling error at the end of the first verse to check).

Here is illustrating example, with CMU Serif, EB Garamond and the commercial font Sabon Next LT Pro, with fragments of a poem (in French) with an overabundance of ss. With fontspec, the option to obtain the long s is StylisticSet=4 or Style=Historic (with possibly some more features)

\documentclass{article}
\usepackage{verse}
\usepackage{color}
\usepackage{fontspec}

\newcommand{\lgS}{\char"017F}
\newcommand{\lgSS}{{\color{red}\char"017F\char"017F}}

\begin{document}

 \begin{verse}[1em]
 \setmainfont[Ligatures = Rare, Style=Historic]{Sabon Next LT Pro}%
\poemtitle{Complainte amoureuse}
 Ah! fallait-il que je vous visses, \\
 Fallait-il que vous me plussiez, \\
 Qu’ingénument je vous le disse, \\
 Qu’avec orgueil vous vous tussiez !
   \end{verse}

\setmainfont[Ligatures = Rare, Style=Historic, StylisticSet =4]{CMU Serif}%
    \begin{verse}[1em]
 Fallait-il que je vous aimasse,\\
 Que vous me désespérassiez,\\
 Et qu’en vain je m’opiniâtrasse,\\
 Et que je vous idolâtrasse\\
 Pour que vous m’a\lgSS a\lgSS ina\lgSS iez !
   \end{verse}

\setmainfont[Ligatures = Rare, Style=Historic]{EB Garamond}%
\begin{verse}[1em]
 Fallait-il que je vous aimasses,\\
 Que vous me désespérassiez,\\
 Et qu’en vain je m’opiniâtrasse,\\
 Et que je vous idolâtrasse\\
 Pour que vous m’a\lgSS a\lgSS ina\lgSS iez !
 \end{verse}

\end{document} 

Answer 2

Under both LuaLaTeX and XeLaTeX, the character -- "LATIN SMALL LETTER LONG S" in Unicode parlance -- may be typeset by inputting \char"0017F.

The default font under both LuaLaTeX and XeLaTeX is Latin Modern. To use a different Opentype font, be sure to load the fontspec package and issue suitable \setmainfont and \setsansfont directives.

%%% compile with either LuaLaTeX or XeLaTeX
\documentclass{article} 
\begin{document}
\char"017F
\end{document}