reporting error from function

[laxmanscdot]

hi all,
When the processing error is more than two, than which approach is better(as mentioned below):

Say the error may be
ERR_A
ERR_B
ERR_C
ERR_D

1) one approach could be function it self return the error code and it is the responsibility of caller to intialize the error.
2) Another the function return either bool or void and the function itself set the error. As we do in the C for example in the case of file open

please suggest pros and cons..
Laxman Singh

[pukur123]

I don't know whether you are talking about standard APIs or user defined functions.

In case of standard APIs, if the API fails, the API will set corresponding the error values (if any defined in the manual page for that API) to the variable "errno" which is defined in the header file error.h.

In case of user defined functions, we can not return more than one value. So if we expecting four error values and one return value from a function, we have to pass the reference of four local variables to the function as arguments.

[laxmanscdot]

I don't know whether you are talking about standard APIs or user defined functions.

In case of standard APIs, if the API fails, the API will set corresponding the error values (if any defined in the manual page for that API) to the variable "errno" which is defined in the header file error.h.

In case of user defined functions, we can not return more than one value. So if we expecting four error values and one return value from a function, we have to pass the reference of four local variables to the function as arguments.

**
As approach is concern how it is differ for standard API and user defined function. In user defined function also you can use unique error codes(declared one of the header file) and those error code could be return or set to some global variable (say cn_error).

why can i not return more than one value from user defined function ? Because if my return type is 'unsigned char' then i could able to return multiple error codes by simply returning (i.e. return ERR_A).

please suggest some pros and cons.

Laxman Singh