#!/usr/local/bin/perl -w
use strict;

open(FILE, ">/tmp/blah") || die "Can Not Open File\n";

my $oldfh = select(FILE);  # $oldfh stores the original filehandle
                           # and FILE becomes the current filehandle
                           # for output

for (my $n = 1; $n < 10; $n ++) {
                           # use backticks as noted elsewhere
    print `ping -c 1 192.168.1.$n`;
}

select($oldfh);            # select the original filehandle,
                           # just for neatness
close (FILE);