i'm not sure if i get the problem right but this script will find the min of all values in column 2 of all given files and the max of all values in column 3.

you just call it with the file names as arguments.

#!/usr/bin/perl -w

use strict;

my $min = undef;
my $max = undef;
foreach (@ARGV) {
    open(F, "< $_");
    while(my $line = <F>) {
        chop($line);
        $line =~ s/[\ \t]+/:/g;
        my @p = split(/:/,$line);
        if(!defined($min)) {
            $min = $p[1];
        }
        if(!defined($max)) {
            $max = $p[2];
        }
        if($p[1] < $min) {
            $min = $p[1];
        }
        if($p[2] > $max) {
            $max = $p[2];
        }
    }
    close(F);
}
print "$min $max\n";
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