[nicenight@CSDN ~]# echo $PATH
**********:/usr/local/mysql/bin/:*********
[nicenight@CSDN ~]# ls /usr/local/mysql/bin/
comp_err       my_print_defaults  mysql_convert_table_format  mysql_fix_privilege_tables  mysql_setpermission  replace
isamchk        mysql              mysqld_multi                mysqlhotcopy                mysqlshow            resolveip
isamlog        mysqlaccess        mysqld_safe                 mysqlimport                 mysql_tableinfo      resolve_stack_dump
msql2mysql     mysqladmin         mysqldump                   mysql_install               mysqltest
myisamchk      mysqlbinlog        mysqldumpslow               mysql_install_db            mysql_waitpid
myisam_ftdump  mysqlbug           mysql_explain_log           mysqlmanagerc               mysql_zap
myisamlog      mysqlcheck         mysql_find_rows             mysqlmanager-pwgen          pack_isam
myisampack     mysql_config       mysql_fix_extensions        mysql_secure_installation   perror
[nicenight@CSDN ~]# ls /usr/local/mysql/libexec/
mysqld

------解决方案--------------------
http://dev.mysql.com/doc/refman/5.1/zh/index.html

------解决方案--------------------
/usr/local/mysql/libexec/ 这个目录根本不在你的PATH$ 中