UNIX for Dummies Questions & Answers

I have a file1 that looks like this:

File 1
a b
b c
c e
d e

and a file 2 that looks like this:

File 2
b
c
e
e

Note that file 2 is the right hand column from file1. I want to remove any lines from file1 that begin with the column in file2. In this case the desired output would be

File 3
a b
d e

I think awk would be best, unless someone knows how to grep only looking a specific columns.

thanks in advance!

Try:

Code:

awk 'NR==FNR{a[$1]=1;next}!($1 in a)' file2 file1

Yes! That works! Thank you so much. Would you mind explaining the syntax? I'm not very good at awk and would like to understand it for future reference.

---------- Post updated at 11:46 AM ---------- Previous update was at 11:02 AM ----------

For some reason it's not working on my actual files with look like this

File 1
GEMS_CAM_101_1_a GEMS_CAM_102_1_a
GEMS_CAM_102_1_a GEMS_CAM_103_1_a
GEMS_CAM_103_1_a GEMS_CAM_104_1_a

File 2
GEMS_CAM_102_1_a
GEMS_CAM_103_1_a
GEMS_CAM_104_1_a

output should be:

File 3
GEMS_CAM_101_1_a GEMS_CAM_102_1_a

Any ideas what's going wrong?

It is working for me...

Code:

[root@rhel ~]# cat f1
GEMS_CAM_101_1_a GEMS_CAM_102_1_a
GEMS_CAM_102_1_a GEMS_CAM_103_1_a
GEMS_CAM_103_1_a GEMS_CAM_104_1_a
[root@rhel ~]# cat f2
GEMS_CAM_102_1_a
GEMS_CAM_103_1_a
GEMS_CAM_104_1_a
[root@rhel ~]# awk 'NR==FNR{a[$1]=1;next}!($1 in a)' f2 f1
GEMS_CAM_101_1_a GEMS_CAM_102_1_a

Ahh! I'm so frustrated. I literally do the exact same thing as you and my output file looks exactly like file1. Is there any other possible explanation for this? or am I missing something..I've checked this for like 15 min haha

Show output of

Code:

cat -Te file1

and

Code:

cat -Te file2

with the use of code tags please.

Ya it's weird, it works fine on my computer at home and it works on the fake examples I make up at work but it won't work on the real thing at work. My linux doesn't have internet so I can't really show you but it's the strangest thing. Anyway, your code is definitely good, it's something wrong with my system I guess. Either way thank you for all your help!