unix sort multiple fields

I'm trying to sort the file below as follows:

col1 (Ascending) col2 (Descending) col3 (Ascending) col4 (Descending)

I want to use the -k command, not the +- syntax. I've figured out how to use the old syntax:

sort -t " " +0 -1 +2 -3 +4r testfile

but it's hardly intuitive. I haven't figured out the right way to use the -k option. Thank you.

Here's the testfile:

5 3 2 9
3 4 1 7
5 2 3 1
6 1 3 6
1 2 4 5
3 1 2 3
5 2 2 3

Result:

1 2 4 5
3 4 1 7
3 1 2 3
5 3 2 9
5 2 2 3
5 2 3 1开发者_开发问答
6 1 3 6

You need one of:

sort --key=1,1 --key=2,2r --key=3,3 --key=4,4r
sort -k1,1 -k2,2r -k3,3 -k4,4r

as in the following transcript:

pax$ echo '5 3 2 9
3 4 1 7
5 2 3 1
6 1 3 6
1 2 4 5
3 1 2 3
5 2 2 3' | sort --key=1,1 --key=2,2r --key=3,3 --key=4,4r

1 2 4 5
3 4 1 7
3 1 2 3
5 3 2 9
5 2 2 3
5 2 3 1
6 1 3 6

Remember to provide the -n option if you want them treated as proper numbers (variable length), such as:

sort -n -k1,1 -k2,2r -k3,3 -k4,4r

What about sort -n -k 1n -k 2rn -k 3n -k 4rn?
-k <FIELD><OPT1><OPT2>... where OPT1 and OPt2 are simply sort options, for example n is numeric, r is reverse