linux重定向命令应用及语法

忘了不少东西，无奈写个Blog  Backup:
Linux基本命令：
who查看当前user
ps aux (我经常多一个‘－’，有一行错误信息)
netstat (具体man or info to CC)
shutdown reboot关机命令
shutdown语法：
／sbin/shutdown[-t秒]［－arkhncfF时间］［警告信息］
eg:
／sbin/shutdown -h 10 'Server will be shutdowned after 10 mins'
man下的参数：
OPTIONS
       -r     Requests that the system be rebooted after it has been brought down.
       -h     Requests  that  the  system  be either halted or powered off after it has
              been brought down, with the choice as to which left up to the system.
         
       -H     Requests that the system be halted after it has been brought down.
       -P     Requests that the system be powered off after it has been brought down.
       -c     Cancels a running shutdown.  TIME is not specified with this option,  the
              first argument is MESSAGE.
       -k     Only  send  out  the warning messages and disable logins, do not actually
              bring the system down.
eg:
shutdown -h now/0
shutdown -h 10:00 /*10点关机
shutdown -h ＋10  10mins后关机
shutdown -r now (reboot at once)
shutdown -r +30 'System will reboot in 30mins'
shutdown -k 'System will reboot'(发送警告信息)
reboot命令
shutdown -r now几乎与reboot相同，关机之前输入回填指令：
sync;sync;sync;reboot
fsck - check and repair a Linux file system
fsck /dev/hda7:
To clear the wrong disk block of /dev/hda7 （单人单机模式root）