Question

I have two files I merged them based key using below code

file1
-------------------------------
1      a      t      p      bbb  
2      b      c      f      aaa  
3      d      y      u      bbb  
2      b      c      f      aaa  
2      u      g      t      ccc  
2      b      j      h      ccc

file2
--------------------------------
1   11   bbb  
2   22   ccc  
3   33   aaa  
4   44   aaa  

I merged these two file based key using below code

awk 'NR==FNR{a[$3]=$0;next;}{for(x in a){if(x==$5) print $1,$2,$3,$4,a[x]};  

My question is how I can save $2 of file2 in variable or array and print after a[x] again.
My desired result is :

1 a t p 1   11  bbb  11  
2 b c f 3   33  aaa  33  
2 b c f 4   44  aaa  44  
3 d y u 1   11  bbb  11  
2 b c f 3   33  aaa  33  
2 b c f 4   44  aaa  44  
2 u g t 2   22  ccc  22  
2 b j h 2   22  ccc  22  

As you see the first 7 columns is the result of my merge code. I need add the last column (field 2 of a[x]) to my result.

Important:

My next question is if I have .awk file, how I can use some bash script code like (| column -t) or send result to file (awk... > result.txt)? I always use these codes in command prompt. Can I use them inside my code in .awk file?

Answer 1

Simply add all of file2 to an array, and use split to hold the bits you want:

awk 'FNR==NR { two[$0]++; next } { for (i in two) { split(i, one); if (one[3] == $NF) print $1,$2,$3,$4, i, one[2] } }' file2 file1

Results:

1 a t p 1   11   bbb   11
2 b c f 3   33   aaa   33
2 b c f 4   44   aaa   44
3 d y u 1   11   bbb   11
2 b c f 3   33   aaa   33
2 b c f 4   44   aaa   44
2 u g t 2   22   ccc   22
2 b j h 2   22   ccc   22

Regarding your last question; you can also add ‘pipes’ and ‘writes’ inside of your awk. Here’s an example of a pipe to column -t:

Contents of script.awk:

FNR==NR { 
    two[$0]++
    next
}

{
    for (i in two) {
        split(i, one)
        if (one[3] == $NF) { 
            print $1,$2,$3,$4, i, one[2] | "column -t"
        }
    }
}

Run like: awk -f script.awk file2 file1

EDIT:

Add the following to your shell script:

results=$(awk '

    FNR==NR {
        two[$0]++
        next
    }

    {
        for (i in two) {
            split(i, one)
            if (one[3] == $NF) {
                print $1,$2,$3,$4, i, one[2] | "column -t"
            }
        }
    }
' $1 $2)

echo "$results"

Run like:

./script.sh file2.txt file1.txt

Results:

1  a  t  p  1  11  bbb  11
2  b  c  f  3  33  aaa  33
2  b  c  f  4  44  aaa  44
3  d  y  u  1  11  bbb  11
2  b  c  f  3  33  aaa  33
2  b  c  f  4  44  aaa  44
2  u  g  t  2  22  ccc  22
2  b  j  h  2  22  ccc  22