[FreeRTOS+FAT Standard API Reference]
int ff_errno( void );
File related functions in the standard C library often return 0 for pass, and -1 for fail. If -1 is returned then the reason for the failure is stored in a variable called errno, which must be inspected separately.
FreeRTOS+FAT’s standard stdio style interface maintains an errno variable for each RTOS task. ff_errno() returns the errno value for the calling task.
The file system’s C library style API uses the same errno values
as used by the stanard C library. These
are documented on a separate page.
- The file system’s native API has a more sophisticated error code system, and returns error codes directly from its API functions.