DocumentationMathematicaThe Mathematica BookMathematica Reference GuideListing of C Functions in the MathLink Library
long MLError(MLINK link) returns a constant identifying the last error to occur on link, or 0 if none has occurred since the previous call to MLClearError().
You can get a textual description of errors by calling MLErrorMessage().
Constants corresponding to standard MathLink errors are defined in mathlink.h.
See Section 2.13.13.