use strict;
use warnings;
my $fin = "SELECTDAT2";
my $fout = "myfile";
open my $ih, '<', $fin or die "cannot open $fin for reading, $! ";
open my $oh, '>', $fout or die "cannot open $fout for writing, $! ";
my @records;
my @list; 
my @sorted_recs;
while (<$ih>) {
chomp;
my @tokens = split;
my $SEC1 = $tokens[3];
my $LAT = $tokens[4];
my $LONG = $tokens[5];
my $DEPTH = $tokens[6];
my $NO = $tokens[10];
my $GAP = $tokens[11];
sub records {
my ($SEC1, $LAT, $LONG, $DEPTH, $NO, $GAP) = @records;
push @records, [ $SEC1, $LAT, $LONG, $DEPTH, $NO, $GAP ];
#sort by LONG (index 0=NO, 1=SEC1, 2=LONG, 3=LAT, 4=DEPTH, 5=GAP)
my $records = \@records;
my @sorted_recs = sort { $$records[$a][6] <=> $$records [$b][6] } @records;
return @records;
}
my $nextline = <$ih>;
my $y = $tokens[0], my $m = $tokens[1], my $d = $tokens[2], my $h = $tokens[3];
sub events {
my (@list);
my $nextline = <$ih>;
foreach $nextline (@list) {
my @tokens = split;
my $SOURCE = $tokens[0];
my $PSEC = $tokens[3];
my $PQ = $tokens[4];
my $SSEC = $tokens[7];
my $SQ = $tokens[8];
push @list, [ $SOURCE, $PSEC, $PQ, $SSEC, $SQ];
last if $nextline =~/^\s*$/;
}
return @list;
last; 
}
print $oh events(@list), @sorted_recs, "\n";
}
close ($oh);
close ($ih);