NAME

 IO::Tee	An IO::Handle subclass for emulating 'tee' behaviour

SYNOPSIS

  require IO::Tee;

  # Read from a given handle $ifh while logging to './logfile'
  my($fh) = IO::Tee->new($ifh, IO::File->new('./logfile', 'w'));
  if (!$fh) {
    die $!;
  }

  my($line);
  while (defined($line = $fh->getline())) {
    # Do something here
    ...
  }
  # Write something into a socket while appending to './logfile'
  $fh = IO::Tee->new($ofh, IO::File->new('./logfile', 'a'));
  while (!$done) {
    # Do something here
    ...
    $fh->print($output);
  }

DESCRIPTION

  This module does something very similar to the 'tee'
  program: All input read from or sent to a given IO handle
  is copied to another IO handle. Typically all methods are
  just inherited from IO::Handle. Exceptions are:
  new The constructor receives two handles as arguments: The
  first handle which will be used for reading or
  writing, the second for logging. The constructor
  returns undef, if either of the handles is undef, so
  that you can safely do something like the following:

    my($fh) = IO::Tee->new(IO::File->new('foo', 'r'),
                           IO::File->new('bar', 'w'));
    if (!$fh) {
        die "Error: $!";
    }

  Of course the logging handle must be ready for output.
  The first handle can be used for both reading and
  writing, but that's probably not too much useful, as
  you cannot distinguish the output in the logfile.

COPYRIGHT AND AUTHOR

  Copyright (C) 1998, Jochen Wiedmann
                      Am Eisteich 9
                      72555 Metzingen
                      Germany

                      Phone: +49 7123 14887
                      Email: joe@ispsoft.de

  This module is free software; you can redistribute it
  and/or modify it under the terms of the GNU General Public
  License as published by the Free Software Foundation;
  either version 2 of the License, or (at your option) any
  later version.

  This module is distributed in the hope that it will be
  useful, but WITHOUT ANY WARRANTY; without even the implied
  warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  PURPOSE. See the GNU General Public License for more
  details.

  You should have received a copy of the GNU General Public
  License along with this module; if not, write to the Free
  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA
  02139, USA.

SEE ALSO

  IO::Handle (3), IO::Seekable (3), tee (1)