Some functions in the library set the global variable
errno when an error occurs. The file,
<errno.h>, provides symbolic names for various error codes.
|#define EDOM 33|
|#define ERANGE 34|
Error code for last error encountered by library.
errno holds the last error code encountered by a library function. This variable must be cleared by the user prior to calling a library function.
errnoglobal variable is not safe to use in a threaded or multi-task system. A race condition can occur if a task is interrupted between the call which sets
errorand when the task examines
errno. If another task changes
errnoduring this time, the result will be incorrect for the interrupted task.