Script to copy a file showing progress.

gistfile1.txt

#!/usr/bin/perl
use strict;
use warnings;
use POSIX ":sys_wait_h";

my $from = $ARGV[0];
my $to   = $ARGV[1];

print "Copying $from to $to\n";

$| = -1;

my $pid = fork;
if ($pid) {
    print "parent\n";
} elsif ($pid == 0) {

  system "cp $from $to";
  exit 0;

} else {
    die  "Couldnt fork\n";
}
my $child;
do {
   $child = waitpid(-1, WNOHANG);
   sleep 1;
   print `ls -al $to`;
   print "-";
} while $child >= 0;
print "\nFile has been copied.\n";

Call this script copy_file.pl
Run it like this:
./copy_file /tmp/from_file /tmp/to_file