System Wide Error Codes Overview

This is an overview document of error codes used system APIs.


Provides a core set of error codes that may be returned by System APIs. They are defined in e32err.h.


These error codes are used by System APIs to indicate common mathematical, file, communications, and client/server errors. These error codes are intended to be generic to reflect the fact that many error conditions occur for similar reasons in nearly all software components. The errors may also be returned by non-System APIs where appropriate. APIs may also use additional error codes where the core set is not sufficient.

Error codes are returned to clients in three circumstances:

  • as a simple TInt return value from a synchronous function

  • as a leave code from a leaving function, which can be caught in a trap harness

  • in a request status, when an asynchronous request function completes

The complete list can be found at e32err.h. This not only describes the symbols used in C++ code, but also the numerical values that those symbols represent.

In the code itself, the core list is defined in the header file e32err.h.