Alright, admittedly this is a bit of a messy repository. Nonetheless the code works (and works quite well).
Plot currently requires SDL-1.2 and gtk-2. Gtk is only used for the save-file dialog when saving bitmaps. This bit could safely be removed to create a build free of the Gtk dependency.
Running make will suffice. A make clean is also provided
Help can be found by typing ./plot --usage.
A pretty plot:
./plot 1 --plotcolor 70,70,70 --static -f "-1" --plotcolor 70,70,70 --static -f "Sin[x]" --tangent --aspect --plotcolor 255,0,0 --axescolor 255,255,255 --xtick 0.78539816 --ytick 0.5 --window 1500,400 -f "Cos[x]" --tangent --plotcolor 255,255,0
In theory if you just run plot with no arguments, it should give you an interactive terminal with syntax similar
to that of the static version. This is extremely buggy, however.
I use the linenoise library to have a (somewhat) interactive experience. I also use the Anonymous Pro font, provided under a very liberal license by the folks over at the Open Font Library.