设计的文件系统实现下述的基本操作：建立文件；删除文件；打开文件；关闭文件； 可对文件设置保护措施（读，写，执行）。-the file system is designed to implement basic operations as follow:
create file
delete file
open file
close file
set security measure
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.003849s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.148630s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.002607s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.003250s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.003230s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.006001s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.002845s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.005588s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015023s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.002768s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 300366 [ RunTime:0.001364s ]
