Does the LaTeX kernel define font-shape macros that expand to `it', `sc', etc.?

Question

I need to perform a test on the current font shape. More specifically, I need to detect whether the current font shape is italic or slanted.

Joseph Wright already provided a solution in his answer to Detect which text "mode" (normal, italic, bold, etc.) is currently in use?. For instance, if you define

\newcommand*{\my@test@it}{it}

then

\ifx\f@shape\my@test@it

will be true if the current font shape is italics.

However, as I'm trying to avoid code duplication as much as possible, I'm wondering whether there really is a need to define macros that expands to it (for italics), sl (for slanted), etc. I suspect there may already exist such macros, perhaps defined in the LaTeX kernel. Is that the case? If so, what are those macros called?

Answer 1

I suppose that you are looking for \bfdefault, \itdefault and stuff:

$ for x in bf it sl md up rm sf tt; do texdef -t latex ${x}default; done;

\bfdefault:
\long macro:->bx

\itdefault:
\long macro:->it

\sldefault:
\long macro:->sl

\mddefault:
\long macro:->m

\updefault:
\long macro:->n

\rmdefault:
\long macro:->cmr

\sfdefault:
\long macro:->cmss

\ttdefault:
\long macro:->cmtt

Be careful since they are all \long.

Answer 2

Can easily be extended to what you need

\documentclass{article}
\usepackage[T1]{fontenc}
\makeatletter
\def\getFSh#1/#2/#3/#4\@nil{#4}
\def\getFSe#1/#2/#3/#4\@nil{#3}
\begin{document}
\itshape
\curr@fontshape --> \expandafter\getFSh\curr@fontshape\@nil

\slshape
\curr@fontshape --> \expandafter\getFSh\curr@fontshape\@nil

\bfseries
\curr@fontshape --> \expandafter\getFSe\curr@fontshape\@nil\relax, 
                    \expandafter\getFSh\curr@fontshape\@nil
\end{document}