I have file.txt
A2
RP FAULT
A2
RP FAULT
A2
CELL
A2
CELL
how I can just grep 2 words: A2 & RP FAULT, The result should be :
A2
RP FAULT
A2
RP FAULT
what I try :
cat file.txt | grep -E "A2|RP FAULT"
but the result like this
A2
RP FAULT
A2
RP FAULT
A2
A2
Your grep -E command does what you wrote in the subject, but I guess what you really want is to show the A2 lines with the "status" if the following line is RP FAULT. Right?
cat file.txt | grep -A 1 "A2" | grep -B 1 'RP FAULT'
The -A n shows n lines after the match, the -B n shows lines before.
Option 1: You can try pcregrep instead of regular grep
pcregrep -M "A2\nRP FAULT" file
-M used to match across multiple lines so that we can search for newlines as \n.Option 2: with regular grep
grep -zoP "A2\nRP FAULT" file
Output:
A2
RP FAULT
A2
RP FAULT