我所经历的大文件数据导出（后台执行,自动生成）

 五、下载文件

    文件的下载就好说了，既然已经都生成成功，下载的方法如下：

<spanmicrosoft yahei><span> 1</span><span>public</span><span>function</span><span> execscript_download(){
</span><span> 2</span><span>$filename</span> = <span>$_REQUEST</span>['filename'<span>];
</span><span> 3</span><span>$uid</span> = <span>$_REQUEST</span>['uid'<span>];
</span><span> 4</span><span>$file_dir</span> = STATISTIC_EXPORT_FILE_DIR.<span>$uid</span>.'/'.<span>$filename</span><span>;
</span><span> 5</span><span>if</span> (!<span>file_exists</span>(<span>$file_dir</span><span>)){
</span><span> 6</span><span>header</span>("Content-type: text/html; charset=utf-8"<span>);
</span><span> 7</span><span>echo</span> "File not found!"<span>;
</span><span> 8</span><span>exit</span><span>; 
</span><span> 9</span>         } <span>else</span><span> {
</span><span>10</span><span>ini_set</span>("memory_limit","500M"<span>); 
</span><span>11</span><span>header</span>('Content-Description: File Transfer'<span>);
</span><span>12</span><span>header</span>('Content-Type: application/octet-stream'<span>);
</span><span>13</span><span>header</span>('Content-Disposition: attachment; filename='.<span>basename</span>(<span>$file_dir</span><span>));
</span><span>14</span><span>header</span>('Content-Transfer-Encoding: binary'<span>);
</span><span>15</span><span>header</span>('Expires: ' . <span>gmdate</span>('D, d M Y H:i:s') . ' GMT'<span>);
</span><span>16</span><span>header</span>('Cache-Control: must-revalidate,post-check=0, pre-check=0'<span>);
</span><span>17</span><span>header</span>('Pragma: public'<span>);
</span><span>18</span><span>header</span>('Content-Length: ' . <span>filesize</span>(<span>$file_dir</span><span>));
</span><span>19</span><span>readfile</span>(<span>$file_dir</span><span>);
</span><span>20</span><span>        }
</span><span>21</span><span>22</span>     }</spanmicrosoft>

 六、上线后出现的问题

    本地本来已经测试完毕，可上线后，却出现了奇怪的问题；

    现象描述：

        当在后台点击生成文件，跳转到下载页的时候，因为下载页是显示文件进度的页面，
        竟然出现有时候有刚刚点击的文件进度，有时候没有，就感觉没有生成相应的文件一样；

    解决方法：

        因为数据文件和进度文件都是生成在程序的某个文件夹file中，所以读取的时候都是读取的文件夹下的文件，从而判断显示进度；

        后面才知道，由于后台程序有两台服务器，导致读取以及下载的时候找不到相应的文件夹，两个服务器相应的文件夹弄个共享目录就可以了

 七、相应的后续优化

    由于下载的文件多了，导致文件夹下的文件越来越多，而原来生成的文件是没有价值的，所以加了个定期删除文件的功能，只保留近七天的文件

    当然可以用crontab，只不过我比较懒，是在点击生成文件的时候，判断了一下文件夹中的过期文件，从而删除

<spanmicrosoft yahei><span> 1</span><span>public</span><span>function</span><span> execscript_process_show(){
</span><span> 2</span><span>$this</span>->load->library('smarty'<span>);
</span><span> 3</span><span>$uid</span> = <span>$_REQUEST</span>['uid'<span>];
</span><span> 4</span><span>$url_dir</span> = STATISTIC_EXPORT_FILE_DIR.<span>$uid</span> .'/';<span>//</span><span>@todo</span><span> 5</span><span>if</span>(!<span>is_dir</span>(<span>$url_dir</span><span>)){
</span><span> 6</span>             @<span>mkdir</span>(<span>$url_dir</span>,0777<span>);
</span><span> 7</span><span>        }        
</span><span> 8</span><span>$files</span> = <span>scandir</span>(<span>$url_dir</span><span>);
</span><span> 9</span><span>if</span>(!<span>empty</span>(<span>$files</span><span>)){
</span><span>10</span><span>foreach</span> (<span>$files</span><span>as</span><span>$key</span> => <span>$value</span><span>) {
</span><span>11</span><span>if</span>(<span>$value</span>!='.' && <span>$value</span>!='..'<span>){
</span><span>12</span><span>foreach</span> (<span>$files</span><span>as</span><span>$key</span> => <span>$value</span><span>) {
</span><span>13</span><span>if</span>(<span>$value</span>!='.' && <span>$value</span>!='..'<span>){
</span><span>14</span><span>if</span>(<span>substr</span>(<span>$value</span>, 0 , 5)!="flag_"<span>){
</span><span>15</span><span>$filenamedate</span> = <span>substr</span>(<span>$value</span>, 0,10<span>);
</span><span>16</span><span>$today</span> = <span>date</span>('Y-m-d',<span>time</span><span>());
</span><span>17</span><span>$filenamedate</span> = <span>date</span>('Y-m-d',<span>strtotime</span>(<span>$filenamedate</span>)+(STATISTIC_FILE_EXPIRE_DAY-1)*24*3600<span>);
</span><span>18</span><span>if</span>(<span>$today</span>><span>$filenamedate</span>){<span>//</span><span>文件过期</span><span>19</span>                                     @<span>unlink</span>(<span>$url_dir</span> . <span>$value</span><span>);
</span><span>20</span>                                     @<span>unlink</span>(<span>$url_dir</span> . 'flag_' . <span>$value</span><span>);
</span><span>21</span><span>                                }
</span><span>22</span><span>                            }
</span><span>23</span><span>                        }
</span><span>24</span><span>                    }                    
</span><span>25</span><span>                }
</span><span>26</span><span>            }
</span><span>27</span><span>        }
</span><span>28</span><span>29</span><span>$this</span>->smarty->assign('uid',<span>$uid</span><span>);
</span><span>30</span><span>$this</span>->smarty->display('interact/statistic/execscript.tpl'<span>);
</span><span>31</span>     }</spanmicrosoft>

 八、后记

    大文件的导出大体就是这个样子，欢迎大家吐槽，共同交流；

    当时在用命令行执行方法的时候，也参考了一下相应的资料，记录一下；

<spanmicrosoft yahei>http://blog.csdn.net/yysdsyl/article/details/4636457

http://www.codesky.net/article/201202/163385.html

http://www.cnblogs.com/zdz8207/p/3765567.html

http://blog.163.com/mojian20040228@126/blog/static/4112219320097300922992/

http://php.net/manual/en/features.commandline.php

http://blog.csdn.net/yangjun07167/article/details/5603425

http://blog.csdn.net/yunsongice/article/details/5445448

http://www.cppblog.com/amazon/archive/2011/12/01/161281.aspx

http://blog.51yip.com/tag/proc_open

http://www.justwinit.cn/post/1418/

http://limboy.me/tech/2010/12/05/php-async.html</spanmicrosoft>

以上就介绍了我所经历的大文件数据导出（后台执行,自动生成），包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。