UNIX for Dummies Questions & Answers

I'm a bit confused. I want to intersect two files based on their specific column, let's say column $4 from both files. This is just printing col 4 & 6 of the first and second files, respectively. This doesn't do the intersection.

Give us an sample input and expected output.
You mean coulmn 4 in file1 == column 6 in file2 then print?

Yes, that's what I meant.

Let's say this is my first file:

Code:

a	b	c	d	e	f

And this is the second one:

Code:

1	2	3	4	5	d

This is what I want:

Code:

a	b	c	d	e	f	1	2	3	4	5	d

Code:

awk 'NR==FNR{A[$4]=$0; next} $6 in A{ print A[$6]"\t"$0 }' file1 file2

Great, thanks for your help

---------- Post updated at 07:32 PM ---------- Previous update was at 05:55 PM ----------

Sorry Ahamad to bug you again but I have one more request. This scripts excludes the lines in the first file which don't intersect. I like to print all of the lines in the first file including the ones which don't intersect. Let me make it simple by this example:

File1

Code:

a	b	c	d	e	f
g	h	i	j	k	l

File2

Code:

1	2	3	4	5	d

Output:

Code:

a	b	c	d	e	f	1	2	3	4	5	d
g	h	i	j	k	l

Please let me know if this doesn't make sense to you.

---------- Post updated at 07:44 PM ---------- Previous update was at 07:32 PM ----------

This actually prints the all first file first then it prints the intersect. This will cause a lot of duplicates in my final output.

Code:

awk 'NR==FNR{A[$6]=$0; next} $4 in A{$0=$0"\t"A[$4]} 1' file2 file1

Untested. Note the swap in file names.