#!/usr/bin/perl
use strict;
use warnings;

my $file = $ARGV[0] || 'file.txt';
open (INPUT, '<', $file) or die "Unable to open file for reading : $!"
+;

my @values;
while ( <INPUT> ) {
    chomp;
    my @col = split /\t/;   # Assume basic tab delimited
    push @values, $col[3];  # Column 4 is what we want
}
my $total = 0;
$total += $_ for @values;
my $average = $total / @values;
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Divide by zero protection?

my $average = @values ? $total / @values : 0;
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pbeckingham,
Sure, among other things. I left error handling up as an task for the reader.

next if ! $col[3];
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Cheers - L~R

use warnings;
use strict;
use List::Util qw(sum);

my @list = ();
while (<DATA>) {
    push @list, (split)[1];
}
my $avg = (sum @list) / (scalar @list);
print "Average: $avg\n";
1;

__DATA__
One 1 #First
RedBaloons 99 #Second
Normans 1066 #Third
Thunderkiss 1965 #Fourth
Warhammer 40000 #Fifth
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I'm sure there's a CPAN module that'll do it even better, though. ;)

    my $sum  = 0;
       $sum += $_ for @total;

    my $average = $sum / @total;
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And here is another:

    my $average = 0;
       $average = ($_ * $average + $total[$_]) / ($_ + 1) for 0 .. @to
+tal -1;
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Or as a one-liner (for a space delimited file with the numbers in column 3):

    perl -lane '$a = (($. -1) * $a + $F[2])/$.; END{print $a}' file
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Or if the numbers are in the first column of the file:

    perl -lpe '$,+=$_}{$_=$,/$.' file
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--
John.

#!/usr/bin/perl

use strict;
use warnings;
use List::Util qw( sum );

my @box = ( 100, 200, 300 );
my $average = (@box) ? (sum (@box) / scalar @box) : 0 ;
print $average, "\n";
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Oh, i missed Art_XIVs node, suggesting the same.

my $total=0;
map($total+=$_,@values);
my $average = @values ? $total / @values : 0;
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die,unless@ARGV;for(@ARGV){$n+=$_;$c++;}$t=$n/$c;print $t;
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