open my $FH_infile,  '<', "$in_file"  or die "Can't open $in_file";
open my $FH_outfile, '>', "$out_file" or die "Can't open $out_file";

##</code><code>##

open ( my $FH_infile,  '<', "$in_file" ) or
  die "Can't open $in_file";
open ( my $FH_outfile, '>', "$out_file" ) or
  die "Can't open $out_file";

##</code><code>##

open ( my $FH_infile,  '<', "$in_file" ) or
  die "Can't open $in_file: $!";
open ( my $FH_outfile, '>', "$out_file" ) or
  die "Can't open $out_file: $!";