who命令的具体实现，方法见原代码注释
/*who1.c - for a first version the who programe
* open,read UTMP file,and show resulets
-/*who1.c- for a first version the who programe
* open,read UTMP file,and show resulets
*/
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001610s ]
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:0.104922s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001167s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001497s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000964s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003687s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000801s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003788s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015215s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.000971s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 178914 [ RunTime:0.035360s ]
