Recursive grep for gz files search string from an output string - linux

Question

I'm trying to search a string from an output of a string in recursive search with gz files folder.
I'm using the command which is only worked:
find . -name "*.gz" -exec zgrep -H 'PATTERN' \{\} \;
from find string inside a gzipped file in a folder
How can I make this happen just like using normal grep with pipe as follow?
cat <folder> | grep 'pattern1' | grep 'pattern2'

Answer 1

you can pipe the find results through a second grep:
find . -name "*.gz" -exec zgrep -H "PATTERN1" {} \; | grep "PATTERN2"

Answer 2

Regarding your specific question
How can I make this happen just like using normal grep with pipe: cat | grep 'pattern1' | grep 'pattern2'
You can use find to cat all the files and then grep, but this won't be good because you will only get result lines without the filename.
It's better to just use two grep commands:
zgrep 'pattern1' *.gz | grep 'pattern2'
If you want to include subdirectories you can use the globstar (assuming you are running bash):
shopt -s globstar
zgrep 'pattern1' **.gz | grep 'pattern2'

Answer 3

By your "pseudo-code" (cat | grep 'pattern2' | grep 'pattern3') do you mean?
If we have a file file.txt that contains:
pattern this text on the line <br>
pattern2 this text on the line <br>
this pattern3 <br>
pattern2pattern3 this line
then your "pseudo-code"
cat file.txt | grep 'pattern2' | grep 'pattern3'
would result in: pattern2pattern3 this line. If this is what you want, we could use
zcat file.gz | grep 'pattern1' | grep 'pattern2'
But if we look at the find . -name "*.gz" -exec zgrep -H 'PATTERN' \{\} \; it is not even close to the samt thing because that would be more like:
cat /**.*txt | grep 'pattern'
which it self is a bit special the samt result would be given by
grep -R 'pattern'
Then i would say it in the case of .gz (not sure if the /**/*.gz will work with zcat)
zcat /**/*.gz | grep 'pattern'