Shell Programming and Scripting

Hi,

How I can merge two file columns such as the followings using awk:
file 1
2 3
2 2
1 1
file 2
4 3
4 5
7 6

Result:
2 3 4 3
2 2 4 5
1 1 7 6

This is an example, at the end, I will have about 25 files that I want to merge them, it is important for me that the order in the columns merged will be the order of the files.

Sorry for my simple questions but I am so new in programming and awk but I have to do a lot.

Thank you so much.

You can use paste command to achieve this:-

Code:

paste file1 file2

My files will be so huge, of about 50 fields and 400,000 rows, using paste, won't it take too much of the memory?

I'm not sure about the memory utilization. If you insist a solution using awk here it is:-

Code:

awk 'NR==FNR{a[FNR]=$0;next} {print a[FNR], $0 } ' file1 file2

that works perfect, thank you so much.

Alternative awk:

Code:

awk '{getline $(NF+1)<f}1' f=file2 file1

It works well with 2 files but when I add a third file with the same number of lines but different number of columns, that is for example:
snp123
snp456
snp789

it doesn't work. Also, when I want to add three files like each other for example:
1 2
1 2
2 3

it also doesn't give me the right file format.

What I want to do finally is merging one file with one column and 25 files each with 2 columns into each other, at the end I will have a file with 26 columns and the number of rows of all files are equal.

Thank you so much for your help.