grep -P -c

Shell Programming and Scripting
1

Hi,

I have a file with lots of lines as follows.

-----------------

AAK40388.1_4 1.4.3.19
AAK40389.1_4 1.5.1.12
AAK40395.1_3 1.1.1.205
AAK40400.1_3 1.1.1.-
AAK40402.1_1 1.17.4.1
AAK40409.1_4 1.9.3.1
AAK40433.1_3 1.18.1.-
AAK40461.1_2 1.1.1.103
AAK40465.1_1 1.1.1.205
AAK40466.1_1 1.2.4.1
AAK40479.1_1 1.8.1.14

---------------

I used following code:

for i in {1..18}
do
     grep -P -c '_1 1\.$i\.' file >> g
done

But it returns all zero. I think the problem lies in '$', which represents an end character in Perl. As I do need a loop, so can you please tell me how to solve it?

Thanks a lot!
Dawn

2

Variables do not expand in single quotes. Try double quotes.

I'm still not sure whether your program will function properly however, because you haven't explained your intention or purpose here.

3

Thanks a lot for your answer. It works! I didn't differentiate between single and double quotes.