EvaluatePacket[expr] is a MathLink packet requesting evaluation of expr.
ReturnPacket[expr] is a MathLink packet that contains the expression expr, the result of an EvaluatePacket evaluation.
EnterExpressionPacket[expr] is a MathLink packet that requests the evaluation of expr.
ResumePacket[] is a MathLink packet used for synchronization with the Mathematica kernel.
SuspendPacket[] is a MathLink packet used for synchronization with the Mathematica kernel.
ReturnTextPacket[string] is a MathLink packet containing string, the result of an EnterTextPacket evaluation.
InputNamePacket[string] is a MathLink packet that contains in string the name to be assigned to the next input.
OutputNamePacket[string] is a MathLink packet that contains in string the name assigned to the next output.
TextPacket[string] is a MathLink packet containing string, the text output from Mathematica as produced by functions such as Print.
mprep
(Mathematica System Program) mprep options template.tm preprocesses the MathLink template file template.tm, and generates C code that contains all the necessary MathLink code to call C functions from ...