Use grep in Mac Terminal

I use Terminal in Mac with the follow开发者_如何学JAVAing command:

   df -lak | grep File||disk02

what I want to use this script to get the header of df command (disk space) and the line with disk02 only. I think '|' is a char in grep as or logic. However, since I am using grep in Terminal, the char '|' also means pipe. Therefore I tried to use '||' to avoid piping, but it does not get what I want. Only the header with "File" is back.

Not sure how I can use this script command in Terminal?

df -lak | grep "File\|disk02"

use awk

df -lak  | awk 'NR==1 || /disk02/'

Or

df -lak | grep -E "File|disk02"

df -lak | grep -E '(^File|disk02)'

You can shorten grep -E to egrep.

df -lak | grep -e File -e disk02

Just display the mount points you're interested in!

df -lak /