如果file1的B列= file2的B列，则将A列file1替换为file2的A列

Question

I have two files of different lengths, with file2 being a big reference file, which I extract data from for file 1.

I have a line of awk which I normally tweak to do find and replace in my files, but it is always find and replace in the same column.

So for something like, if $1 of file1 = $7 of file2, replace $1 of file1 with $2 of file2, I would normally use:

awk 'FNR==NR{a[$7]=$2;next}a[$1]{$1=a[$1]}1' file2 file1 > newfile

However, I am trying to think of a way to code:

If $2 of file1 = $2 of file2, replace $1 file1 with $1 of file2.

But in the above code, I do not know which $1 refers to "find" and which $1 refers to "replace".

file1 looks like

0   rs58108140  0   0   G   A   
0   rs189107123 0   0   C   G
0   rs180734498 0   0   C   T

file2 looks like

1   rs58108140  0   10583   G   A   1:10583
1   rs189107123     0   10611   C   G   1:10611
1   rs180734498     0   13302   C   T   1:13302

Desired output would be:

1   rs58108140  0   10583   G   A
1   rs189107123     0   10611   C   G
1   rs180734498     0   13302   C   T 

Thanks in advance for any help given.

Answer 1

这个单行将做：

awk 'NR==FNR{a[$2]=$1;b[$2]=$4;next}$2 in a{$1=a[$2];$4=b[$2]}7' f2 f1