Question

I am not sure why this Perl sorting is not working.
Please suggest how to resolve this.

while (<>) {

    chomp;
    if (/VIOLATE/) {

        @lines = split " ", $_;
        #print "$lines[-2]\n";  ## Print last but one column
        my @viol = "$lines[-2]\n";

        @sorted = sort {$a <=> $b} @viol;
        print "@sorted";
    }
};

Command : perl test.pl test.log

test.log :

0.98           2.04          -1.106  VIOLATE
0.98           2.04          3.06
0.98           2.04          -11.06  VIOLATE
0.98           2.04          -1.06  VIOLATE
0.98           2.04          1.06 
0.98           2.04          -0.226  VIOLATE
0.98           2.04          -2.06  VIOLATE

Answer 1

Are you trying to match any line with VIOLATE in it, put the result in an array then sort all the violations? If so you need to declare and sort @viol outside the loop:

use strict;
use warnings; # Don't forget these!

my @viol;

while (<>) {
    chomp;
    if (/VIOLATE/) {
        my @lines = split(/\s+/); # Split on one or more whitespace characters.
        push @viol, $lines[-2];
    }
}

# sort and print
my @sorted = sort {$a <=> $b} @viol;
print "@sorted";

This outputs: -11.06 -2.06 -1.106 -1.06 -0.226