Example 8-8. tctee

  #!/usr/bin/perl
  # tctee - clone that groks process tees 
  # perl3 compatible, or better.
  
  while ($ARGV[0] =~ /^-(.+)/ && (shift, ($_ = $1), 1)) {
      next if /^$/;
      s/i// && (++$ignore_ints, redo);
      s/a// && (++$append,      redo);
      s/u// && (++$unbuffer,    redo);
      s/n// && (++$nostdout,    redo);
      die "usage $0 [-aiun] [filenames] ...\n";
  }
  
  if ($ignore_ints) {
      for $sig ("INT", "TERM", "HUP", "QUIT") { $SIG{$sig} = "IGNORE"; }
  }
  
  $SIG{"PIPE"} = "PLUMBER";
  $mode = $append ? ">>" : ">";
  $fh = "FH000";
  
  unless ($nostdout) {
      %fh = ("STDOUT", "standard output"); # always go to stdout
  }
  
  $| = 1 if $unbuffer;
  
  for (@ARGV) {
      if (!open($fh, (/^[^>|]/ && $mode) . $_)) {
          warn "$0: cannot open $_: $!\n"; # like sun's; i prefer die
          $status++;
          next;
      }
      select((select($fh), $| = 1)[0]) if $unbuffer;
      $fh{$fh++} = $_;
  }
  
  while (<STDIN>) {
      for $fh (keys %fh) {
          print $fh $_;
      }
  }
  
  for $fh (keys %fh) {
      next if close($fh) || !defined $fh{$fh};
      warn "$0: couldnt close $fh{$fh}: $!\n";
      $status++;
  }
  
  exit $status;
  
  sub PLUMBER {
      warn "$0: pipe to \"$fh{$fh}\" broke!\n";
      $status++;
      delete $fh{$fh};
  }