This is really basic stuff, and you should really grab a book (Learning Perl or Programming Perl for example) or even have a look at the docs.

Now for the task at hand just use:

#!/bin/perl -w
use strict;

my $file= shift or die "usage $0 <file>";

open( FILE, "<$file") or die "cannot open $file: $!";

while( my $device_id= <FILE>)
  { chomp $device_id; # removes the end of line
    unless( $device_id=~ /^\d{10}$/)
      { die "invalid device id: $device_id"; }
    # do your stuff here
  }
[download]

Just make sure you understand what the code does before and why you should write it along those lines before using it.

Update: Oh my god! There is no review for Programming Perl in the review section, link removed. Somebody _please_ post a review!