Extract lines containing PAT1 but not PAT2 with sed

Question

I want to extract the lines containing PAT1 but not PAT2 from a file. For example, with PAT1='dog', PAT2='cat', and the following input:

1 cat chicken
2 bird dog apple
3 dog orange cat
4 cat juice coffee
5 cow milk dog

I want the following output:

2 bird dog apple
5 cow milk dog

Answer 1

Something like:

sed '/dog/!d;/cat/d'

See also

grep dog | grep -v cat

Answer 2

You can do it like this :

sed -n '
    /dog/{
        /cat/!{
            p
        }
    }
' file.txt

or with awk :

awk '/dog/ && !/cat/' file.txt

later one have the advantage to be very clear & simple to remember.

or using perl

perl -ne 'print if /dog/ && !/cat/' file.txt