Shell Programming and Scripting

Hi all,

I've searched the forum and I can find some code to sort uniquely in perl but not by a single field.

I have a file with data such as the following:

1,test,34
1,test2,65
2,test,35,
1,test3,34
2,test,34

What i want to do is sort it uniqely by the first field only so I'd end up with

1,test,34
2,test,35

or

1,test2,65
2,test,34

or any combination just so long as I have a unique value in the first field.

I don't care if any of the other fields have duplicates e.g I don't care that line 1 has test,34 and so does the last line, I don't want to sort uniquely like this I only care if the first field has a duplicate entry.

I hope that makes sense, I look forward to your responses.

Many thanks!!!

Code:

#!/usr/bin/perl

use warnings; 
use strict;

my %H;

  while (<DATA>) {
    my @F = split ',';
    print unless $H{$F[0]}++;
}

__DATA__
1,test,34
1,test2,65
2,test,35,
1,test3,34
2,test,34

Which outputs:

Code:

% ./s
1,test,34
2,test,35,

On the command line you could use something like this:

Code:

% perl -F, -lane'print unless $_{$F[0]}++' infile 
1,test,34
2,test,35,

With awk it's just:

Code:

% awk -F, '!_[$1]++' infile
1,test,34
2,test,35,

On Solaris you should use nawk, /usr/xpg4/bin/awk or gawk.

Thanks, the first solution works nicely!