my $myvar;
{
  local $/ = undef;
  if ( ( $myvar = <FILEPTR> )  =~ s/\n+//g ) {
    alert_user();
  } 
}

##</code><code>##

( $myvar = <FILEPTR> )  =~ s/\n+//g;

##</code><code>##

local $/ = undef;

##</code><code>##

s/\n+(?!\z)//g

##</code><code>##