#include <aio.h> ssize_t aio_return(struct aiocb *aiocbp);
The aio_return() function returns the return status associated with the aiocb structure referenced by the aiocbp argument. The return status for an asynchronous I/O operation is the value that would be returned by the corresponding read(2), write(2), or fsync(3C) function call. If the error status for the operation is equal to EINPROGRESS, then the return status for the operation is undefined. The aio_return() function may be called exactly once to retrieve the return status of a given asynchronous operation; thereafter, if the same aiocb structure is used in a call to aio_return() or aio_error(3C), an error may be returned. When the aiocb structure referred to by aiocbp is used to submit another asynchronous operation, then aio_return() may be successfully used to retrieve the return status of that operation.
If the asynchronous I/O operation has completed, then the return status, as described for read(2), write(2), and fsync(3C), is returned. If the asynchronous I/O operation has not yet completed, the results of aio_return() are undefined.
The aio_return() function will fail if:
The aiocbp argument does not refer to an asynchronous operation whose return status has not yet been retrieved.
The aio_return() function is not supported by the system.
The aio_return() function has a transitional interface for 64-bit file offsets. See lf64(5).
See attributes(5) for descriptions of the following attributes:
close(2), exec(2), exit(2), fork(2), lseek(2), read(2), write(2), fsync(3C), aio.h(3HEAD), signal.h(3HEAD), aio_cancel(3C), aio_fsync(3C), aio_read(3C), lio_listio(3C), attributes(5), lf64(5), standards(5)