Head and hail at the same time

Question

Is there one liner liner for this?

head -n 3 test.txt > out_dir/test.head.txt
grep hello test.txt > out_dir/test.tmp.txt
cat out_dir/test.head.txt out_dir/test.tmp.txt > out_dir/test.hello.txt
rm out_dir/test.head.txt out_dir/test.tmp.txt

Ie, I want to get the header and some grep lines from the given file at the same time.

Answer 1

Use awk:

awk 'NR<=3 || /hello/' test.txt > out_dir/test.hello.txt

Answer 2

You can say:

{ head -n 3 test.txt ; grep hello test.txt ; } > out_dir/test.hello.txt

Answer 3

sed

sed -n '1,3p; /hello/p' test.txt > out_dir/test.hello.txt

Answer 4

awk , sed :

$ sed -n test.txt -e '1,3p' -e '4,$s/hello/hello/p' test.txt > $output_file

-n , , . -e - '1,3p prints ou 4,$s/hello/hello/p , hello, hello . p .

There should be a way to use it 4,$g/HELLO/p, but I could not get it to work. It has been a long time since I really messed up sed.

Answer 5

Of course I would go awk, but here is the edpre- nostalgic solution for pre- vi:

ed test.txt <<%
4,$ v/hello/d
w test.hello.txt
%