Using grep for excluding words-CodePudding

For example my text is like this below.

mykey
nice comment
...
...
mykey
not bad comment
...
...
mykey
nice comment
...
...
mykey
excellent comment

I am using grep such as

$ grep 'mykey' * -1 | wc -l
$ 4

$ grep 'mykey' * -1 | grep 'nice comment' | wc -l
$ 2

This can check the number of mykey appears and nice comment is succeeded.

Then I want to see where the nice comment is not appeared after mykey.

At first I try this ,but it was wrong.

grep 'mykey' * -1 | grep -v 'nice comment'

I want to show such as,

mykey
not bad comment

mykey
excellent comment

Is it possible?

CodePudding user response：

I don't think it is possible with grep, but you can use sed:

sed -n '/mykey/{N;/nice comment/!p;}' master.txt

Output:

mykey
not bad comment
mykey
excellent comment

If you only want to count number of "not nice" comments, you could still use two greps:

$ grep -A1 --group-separator= 'mykey' master.txt | grep -v 'nice comment\|mykey\|^$' | wc -l
2