Tizen Native API
3.0
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Error Tutorial
Registering messages
The error module can provide a system that mimics the errno system of the C standard library. It consists in 2 parts:
- A way of registering new messages with eina_error_msg_register() and eina_error_msg_get(),
- A way of setting / getting the last error message with eina_error_set() / eina_error_get().
So one has to first register all the error messages that a program or a library should manage. Then, when an error occurs, use eina_error_set(), and when errors are managed, use eina_error_get(). If eina_error_set() is used to set an error, do not forget to remove previous set errors before calling eina_error_set().
Here is an example for use:
//Compile with: //gcc -g eina_error_01.c -o eina_error_01 `pkg-config --cflags --libs eina` #include <stdlib.h> #include <stdio.h> #include <eina_main.h> #include <eina_error.h> Eina_Error MY_ERROR_NEGATIVE; Eina_Error MY_ERROR_NULL; void *data_new() { eina_error_set(0); eina_error_set(MY_ERROR_NULL); return NULL; } int test(int n) { eina_error_set(0); if (n < 0) { eina_error_set(MY_ERROR_NEGATIVE); return 0; } return 1; } int main(void) { void *data; if (!eina_init()) { printf ("Error during the initialization of eina_error module\n"); return EXIT_FAILURE; } MY_ERROR_NEGATIVE = eina_error_msg_static_register("Negative number"); MY_ERROR_NULL = eina_error_msg_static_register("NULL pointer"); data = data_new(); if (!data) { Eina_Error err; err = eina_error_get(); if (err) printf("Error during memory allocation: %s\n", eina_error_msg_get(err)); } if (!test(0)) { Eina_Error err; err = eina_error_get(); if (err) printf("Error during test function: %s\n", eina_error_msg_get(err)); } if (!test(-1)) { Eina_Error err; err = eina_error_get(); if (err) printf("Error during test function: %s\n", eina_error_msg_get(err)); } eina_shutdown(); return EXIT_SUCCESS; }
Of course, instead of printf(), eina_log_print() can be used to have beautiful error messages.