Some Smac files are provided in this distribution and are known as
SmacLib. These files contain many functions built on the top of the
lower interface of the editor (see Built-in editor function
§4.8 page 
and Xcoral interface §7 page ). These functions are C functions interpreted by Smac.
You can read them in the given files suffixed by .sc, for instance
cmd.sc and head.sc files. They are good examples of Smac
and Xcoral use. I encourage you to read, use and perhaps adapt (correct
?) them.
These files are generally loaded and evaluated during start-up.
(see .xcoralrc file §5.1 page ).
XCORALRC and XCORAL_SMACLIB environment variables are
available at start-up to configure the editor.
XCORALRC is used to specify the path of the .xcoralrc
file (default is $HOME/.xcoralrc) and XCORAL_SMACLIB
the directory path where to find Smac files (default
is the directory specified at compile time: see
XC_LIBDIR in Imakefile, typically /usr/local/lib/xcoral).