UNIX for Dummies Questions & Answers

Hi All,

I have 2 csv files. 1st file has 10 columns and the 2nd file has 12 columns.
The requirement is, if the 4th column of file1 matches with the 4th column of file2, then append the 12th column of file2 with file1.

Both files have equal number of lines and the 4th column values are unique.
I tried the below command after googling. Can some one please explain the command.

Code:

awk -F, 'BEGIN { while (( getline < "file2" )>0) a[$4]=$12 } 
         a[$4] { print a[$4]","$0 }' file1  >  outputFile

The problem is, this command works only if the header in both files are removed. I have 2 lines of header in file1 and 1 line of header in file2. Is there any way to remove the header by tweaking the above command, without creating new files.

Thanks in advance!
Ganesh

Something like this?

Code:

awk 'NR==FNR{a[$4]=$12; next}
FNR>1 && a[$4]{print $0, a[$4]}' file2 file1