Adding columns from multiple files with numbered names

Question

I have a lot of files named like this: DOS1, DOS2, DOS3, DOS4, ..., DOS128. Each file contains four columns (first column is the same) with numbers, like this:

DOS1 is:

33 12 1 2
16 32 8 1
9  90 17 5
...

DOS2 is:

33 1 2 1
16 3 4 3
9  1 1 1
...

I would like to sum the second, third and four column from specified DOSX files, for example DOS1 and DOS2, to get DOS_sum:

33 13 3 3
16 35 12 4
9  91 18 6
...

How can I do this?

Answer 1

With awk:

awk '{a[FNR]=$1;b[FNR]+=$2;c[FNR]+=$3;d[FNR]+=$4} END{for (i=1;i<=FNR;i++) print a[i], b[i], b[i], d[i]}' DOS1 DOS2 > DOS_sum

More readably:

{
    a[FNR]=$1     # Keep the first column
    b[FNR]+=$2    # Sum the rest. FNR is the current line number 
    c[FNR]+=$3    # in the current file. So this accumulates
    d[FNR]+=$4    # the values of a given line number across files.
}
END {
    for (i=1; i<=FNR; i++) 
        print a[i], b[i], c[i], d[i]
}

Use bash's brace expansion to sum a sequence of files:

awk '{a[FNR]=$1;b[FNR]+=$2;c[FNR]+=$3;d[FNR]+=$4} END{for (i=1;i<=FNR;i++) print a[i], b[i], b[i], d[i]}' DOS{10..73}