Linux sort
 

Hi,

I need to sort data numerically by first column and if they are equal then by second column. The columns are separated by spaces and the data looks something like this.

-9.21572e-19 0.812056
0.0275 0.812056
-0.0275 0.814485
0.055 0.812056
-0.055 0.820524
0.0825 0.812056
-0.0825 0.832067
-0.085028 0.833333
0.11 0.812056
-0.11 0.848593
-0.120218 0.85625
0.1375 0.812056

Could someone help me out how to write a script for this. I tried the following but it doesnt seem to work.

sort -t ' ' -k1,1n -k2,2nr file.txt

Thanks,
Anks

When you say "doesn't work", can you be more specific? i.e. tell us what DOES happen.

I wonder if the minus signs are relevant to what is happening?

From the sort man page: I think the number in scientific notation will be a problem though. [ EDIT: Never mind. Posted before trying it]

This works in perl:

I slightly changed your data so you would see that it works if the first value is equal.

Brian

Just to clarify my previous post (#3): setting the -g switch works.
The edit was about my comment on the number in scientific notation.

Using Brian's data:

Hey Norobro,

Thats exactly the kind of output I want but how did you get it to work.

sort -g -k1 -k2 sort.txt

doesnt help me out. It seems to ignore the negative signs before the numbers. It gives exactly the same output as the numbers in the orginal file without doing any sorting for the file I gave.

I am working on mandriva, I am so annoyed that I am caught in something so trivial and my work is stuck.

I do not wish to go for a C or perl code when I believe this can be done in one line. Please help me out.

Regards,
Anks

sort -n -t' ' sort.txt

I added an additional line in the data to check second column sorting.
But if you use scientific notation, you may need to use a generic sort (-g) instead.

Edit: jschiwal beat me! ;)

pixellany, you got it right, it has to do something with the minus sign...if I keep all the numbers positive it is working well.

It somehow seems to be ignoring the negative signs while sorting. I tried all the above responses but it doesnt help. Could it be a bug (I am on Mandriva), or some kind of setting needs to be done so that negative signs are not ignored.

Can you elaborate, please? Copy and paste what do you see in your terminal, otherwise we cannot be of much help. The following is a working example showing the input, the command, the output:

Anks,

As I indicated in my post I used the Brian's (BCarey) data to test for identical first columns. As Colucix pointed out the command can be shortened to:We have a pretty good sampling of distros in this thread where the sort command works. I can't imagine that Mandriva would be any different.

Just a shot in the dark, but could this be your problem? From the sort man page:

Hey Guys,

Here is a screenshot of the shell. See if this can be of any help for you guys in finding the problem.

Thanks,
Anks

I agree with norobro's suggestion. Maybe your current LOCALE affects the sort order. Please try

Superb Guys,

It works :-)

Thanks a lot for all your effors and help. I was really banging my head on my comp for this trivial problem.

Anks

Nice to hear the good news! For your information, you can use the command
to see the current settings based on the language you chose for your computer. They affect the behaviour of many different commands. Even a simple ls can sort entries in a different way if you change your current locale settings. Giving a different environment to some specific commands, using the env method as suggested above, is a very common task in order to prevent strange or unexpected behaviours.

Cheers! :)