sort by the maximum of the first two columns

Question

I have a file that contains:

1 1 1 1 text1
7 9 4 2 text2
2 2 0.5 0.7 text3
5 4 1 2 text4

I want to sort it (output to the terminal) according to the maximum of the first two columns.

expected output:

1 1 1 1 text1
2 1 0.5 0.7 text3
5 4 1 2 text4
7 9 4 2 text2

how can this be achieved? thanks!

Answer 1

Your input file is:

1 1 1 1 text1
7 9 4 2 text2
2 2 0.5 0.7 text3
5 4 1 2 text4

With this input a simple sort will work:

$ sort << EOF
> 1 1 1 1 text1
> 7 9 4 2 text2
> 2 2 0.5 0.7 text3
> 5 4 1 2 text4
> EOF
1 1 1 1 text1
2 2 0.5 0.7 text3
5 4 1 2 text4
7 9 4 2 text2

If we amend the input to something like...

$ cat test.txt
1 3 1 1 text1
7 9 4 2 text2
2 1 0.5 0.7 text3
5 4 1 2 text4

Then the input becomes challenging. A simple sort no longer works, and we can test other approaches:

$ sort -k1,1n -k2,2n < test.txt
1 3 1 1 text1
2 1 0.5 0.7 text3
5 4 1 2 text4
7 9 4 2 text2

This isn't what we'd expect - The first two lines of output are reversed - the highest 1/2 column value in line 1 is "3", and the highest in line 2 is "2".

The following appears to work, at least for the revised input file, but it's not pretty (my awk-fu is weak):

$ awk '{ sorton=$1; if ($2>$1) { sorton=$2 }; print $1, $2, $3, $4, $5, sorton }' < test.txt | sort -k 6 | cut -d " " -f 1-5
2 1 0.5 0.7 text3
1 3 1 1 text1
5 4 1 2 text4
7 9 4 2 text2

@Nominal-Animal and @JJoao suggested refinements, resulting in:

$ awk '{ k= $1>$2 ? $1: $2 ; print k, $0 }' test.txt | sort -g | cut -d ' ' -f 2-
2 1 0.5 0.7 text3
1 3 1 1 text1
5 4 1 2 text4
7 9 4 2 text2

(Feel free to edit this post to refine an awk solution.)

Answer 2

For Numerical Sort in the Two first columns

sort -n -t " " -k1,1 -k2,2 /path/to/file

Answer 3

You can do that with GNU sort:

sort -k1,1n -k2,2n yourfile

• -k for specify the column

Answer 4

If you have GNU awk (gawk) as your awk, you can use its asort() function to do everything inside of awk itself:

{
  max = $1 > $2 ? $1 : $2;
  if (max in lines)
    lines[max] = lines[max] ORS $0
  else
    lines[max] = $0
}

END {
  asort(lines, lines, "@ind_num_asc")
  for(i=1; i<=length(lines); i++) { print lines[i] }
}