oracular (3) aio_write.3.gz

Provided by: manpages-dev_6.8-2_all bug

NAME

       aio_write - asynchronous write

LIBRARY

       Real-time library (librt, -lrt)

SYNOPSIS

       #include <aio.h>

       int aio_write(struct aiocb *aiocbp);

DESCRIPTION

       The  aio_write()  function  queues  the  I/O  request described by the buffer pointed to by aiocbp.  This
       function is the asynchronous analog of write(2).  The arguments of the call

           write(fd, buf, count)

       correspond (in order) to the fields aio_fildes, aio_buf, and aio_nbytes of the structure  pointed  to  by
       aiocbp.  (See aio(7) for a description of the aiocb structure.)

       If  O_APPEND  is  not  set,  the  data  is  written starting at the absolute position aiocbp->aio_offset,
       regardless of the file offset.  If O_APPEND is set, data is written at the end of the file  in  the  same
       order as aio_write() calls are made.  After the call, the value of the file offset is unspecified.

       The  "asynchronous"  means that this call returns as soon as the request has been enqueued; the write may
       or may not have completed when the call returns.  One  tests  for  completion  using  aio_error(3).   The
       return  status  of a completed I/O operation can be obtained aio_return(3).  Asynchronous notification of
       I/O completion can be obtained by setting aiocbp->aio_sigevent  appropriately;  see  sigevent(3type)  for
       details.

       If  _POSIX_PRIORITIZED_IO  is  defined,  and  this  file  supports it, then the asynchronous operation is
       submitted at a priority equal to that of the calling process minus aiocbp->aio_reqprio.

       The field aiocbp->aio_lio_opcode is ignored.

       No data is written to a regular file beyond its maximum offset.

RETURN VALUE

       On success, 0 is returned.  On error, the request is not enqueued, -1 is returned, and errno  is  set  to
       indicate  the  error.  If an error is detected only later, it will be reported via aio_return(3) (returns
       status -1) and aio_error(3) (error status—whatever one would have gotten in errno, such as EBADF).

ERRORS

       EAGAIN Out of resources.

       EBADF  aio_fildes is not a valid file descriptor open for writing.

       EFBIG  The file is a regular file, we want to write at least one byte, but the starting position is at or
              beyond the maximum offset for this file.

       EINVAL One or more of aio_offset, aio_reqprio, aio_nbytes are invalid.

       ENOSYS aio_write() is not implemented.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌──────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │InterfaceAttributeValue   │
       ├──────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │aio_write()                                                                   │ Thread safety │ MT-Safe │
       └──────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       POSIX.1-2008.

HISTORY

       glibc 2.1.  POSIX.1-2001.

NOTES

       It  is a good idea to zero out the control block before use.  The control block must not be changed while
       the write operation is in progress.  The buffer area being written out must not be  accessed  during  the
       operation or undefined results may occur.  The memory areas involved must remain valid.

       Simultaneous I/O operations specifying the same aiocb structure produce undefined results.

SEE ALSO

       aio_cancel(3),  aio_error(3),  aio_fsync(3),  aio_read(3),  aio_return(3), aio_suspend(3), lio_listio(3),
       aio(7)