Function pwrite

components/dfs/dfs_v2/src/dfs_posix.c:1432–1464

* this function is a POSIX compliant version, which will write specified data * buffer length for an open file descriptor. * * @param fd the file descriptor * @param buf the data buffer to be written. * @param len the data buffer length. * @param offset the file pos * * @return the actual written data buffer length. */

 * @return the actual written data buffer length.
 */
ssize_t pwrite(int fd, const void *buf, size_t len, off_t offset)
{
    ssize_t result;
    off_t fpos;
    struct dfs_file *file;

    if (buf == NULL)
    {
        rt_set_errno(-EBADF);
        return -1;
    }

    file = fd_get(fd);
    if (file == NULL)
    {
        rt_set_errno(-EBADF);

        return -1;
    }
    /* fpos lock */
    fpos = dfs_file_get_fpos(file);
    result = dfs_file_pwrite(file, buf, len, offset);
    /* fpos unlock */
    dfs_file_set_fpos(file, fpos);
    if (result < 0)
    {
        rt_set_errno(result);

        return -1;
    }

    return result;
}
RTM_EXPORT(pwrite);

/**@}*/