NAME

       aio_write - asynchronous write

SYNOPSIS

       #include <aio.h>

       int aio_write(struct aiocb *aiocbp);

       Link with -lrt.

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 file offset aiocbp->aio_offset,
       regardless of the current 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 current 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(7) 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
       appropriately.  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.

VERSIONS

       The aio_write() function is available since glibc 2.1.

ATTRIBUTES

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

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

CONFORMING TO

       POSIX.1-2001, POSIX.1-2008.

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)

COLOPHON

       This  page  is  part  of  release  4.04  of  the  Linux man-pages project.  A description of the project,
       information  about  reporting  bugs,  and  the  latest  version  of  this   page,   can   be   found   at
       http://www.kernel.org/doc/man-pages/.

                                                   2015-03-02                                       AIO_WRITE(3)