From PHP 4.0.2, an additional 3 optional parameters are supplied: the filename in which the error occurred, the line number in which the error occurred, and the context in which the error occurred (an array that points to the active symbol table at the point the error occurred).
The user function needs to accept 2 parameters: the error code, and a string describing the error. From PHP 4.0.2, an additional 3 optional parameters are supplied: the filename in which the error occured, the line number in which the error occured, and the context in which the error occured (an array that points to the active symbol table at the point the error occurred).