======簡單過濾MAC======
  - 先建立sample檔<code bash>vim MAC
86:65:0T:E3:B1:DA
62:0D:5B:2D:1F:41
00:11:05:3B:21:E3
76:0E:A1:05:75:57
fekjwejg
A1234r567
#4445ddd192.168.0.245
192.168.1.188
</code>
  - <code bash>$cat MAC|grep -E -o '[0-9|A-Z]{2}\:[0-9|A-Z]{2}\:[0-9|A-Z]{2}\:[0-9|A-Z]{2}\:[0-9|A-Z]{2}\:[0-9|A-Z]{2}' --color</code>或是另一種寫法<code bash>$cat MAC|grep -E -o '([0-9|A-Z]{2}\:){5}[0-9|A-Z]{2}' --color</code>