FILE *pif;
  pif = fopen ( $filename, 'r' );
  if ( pif == NULL ) {

    /* Problem opening file.. */
  }
  ..
  fclose ( pif );

##</code><code>##

  open ( my $in_fh, '<', $filename ) or
    die "Unable to open $filename for read: $!";
  ..
  close ( $in_fh );

##</code><code>##

  use autodie;
  open ( my $in_fh, '<', $filename );
  ..
  close ( $in_fh );