ioErrorFromErrno
Converts errno.h error codes into GIO error codes. The fallback value %G_IO_ERROR_FAILED is returned for error codes not currently handled (but note that future GLib releases may return a more specific value instead).
As %errno is global and may be modified by intermediate function calls, you should save its value as soon as the call which sets it
Return
#GIOErrorEnum value for the given errno.h error number.
Parameters
errNo
Error number as defined in errno.h.