termcalc is a mostly functional command-line calculator.
Use termcalc -h or termcalc --help for a list of acceptable arguments. Interactive mode launches an interpreter and graphing mode launches a graphing calculator.
Just run make. Please note that the makefile, along with the rest of this program, was created on a MacBook, so while it will likely work in OSX, it might not work on some Linux systems and almost certainly won't work on Windows. If it doesn't work for you, create a GitHub issue.