I need a script that copies the filename into the file

Question

I need a script that copies the filename into 4th column of each line in the text doc file.
I have over 2000 different file names each containing 6 columns and ~50-100 rows.
I can do this manually using this script:
awk '{print $1"\t"$2"t\"$3"\t <name> \t"$6}'
But I would like an automation command or script. Is there any command that I can use instead of <name> that will copy the filename into the column?
Thanks
Monica

Answer 1

Oops, I forgot the redirect to a file. It's not a good idea to edit files in place. A script could fail and you're left with at least one file ruined. It's better to create new files then delete the old files.
for file in *; do
    while read col1 col2 col3 col4 col5 col6; do              
        printf "%s\t%s\t%s\t%s\t%s\n" $col1 $col2 $col3 $file $col6
    done < $file > n$file
done
You could narrow the files listed such as
for file in *.tsv
and redirect the new files to another directory. Such as
done < $file > /absolute/path/to/directory/$file