man, info, help, date, hwclock, cal, shutdown, reboot, halt, poweroff, type, cd, which, dirname, basename, who, which, whatis, makewhatis, echo, hash, tty tac:cat按行逆序显示 file FILE...: 查看文件内容的格式 # mkdir `date +%F-%H-%M-%S`创建以当前时间命令目录,例如2014-----; rmdir…