Command line application for calculating a GPA
gpa
provides a simple interface
gpa - Calculate the gpa given a series of (grade, weight) pairs.
Usage:
gpa [(<grade> <credits>)...]
gpa [<file>]
Either invoke it with a letter grade/credit amount pairs as command line parameters, or pass it a file from which to read the pairs.
If neither is specified, it will read from stdin like it would from a file.