Possible completions:
  count                Count occurrences
  display              Show additional kinds of information
  except               Show only text that does not match a pattern    //排除正常数据的关键字，只显示有问题的。
  find                 Search for first occurrence of pattern
  hold                 Hold text without exiting the --More-- prompt
  last                 Display end of output only
  match                Show only text that matches a pattern           //只查看带关键字的内容。
匹配多个单词：match "CPU|Mem"        //匹配含有CPU或者Mem的行

  no-more              Don't paginate output                           //不分页输出，默认是分页的。
  refresh              Refresh a continuous display of the command
  request              Make system-level requests
  resolve              Resolve IP addresses
  save                 Save output text to file                       
  trim                 Trim specified number of columns from start of line //从第一行修剪指定列号