Tee - Pure Perl emulation of GNU tee


version 0.14


  # from Perl
  use Tee;
  tee( $command, @files );
  # from the command line
  $ cat README.txt | ptee COPY.txt


The Tee distribution provides the ptee program, a pure Perl emulation of the standard GNU tool tee. It is designed to be a platform-independent replacement for operating systems without a native tee program. As with tee, it passes input received on STDIN through to STDOUT while also writing a copy of the input to one or more files. By default, files will be overwritten.

Unlike tee, ptee does not support ignoring interrupts, as signal handling is not sufficiently portable.

The Tee module provides a convenience function that may be used in place of system() to redirect commands through ptee.



   tee( $command, @filenames );
   tee( $command, \%options, @filenames );

Executes the given command via system(), but pipes it through ptee to copy output to the list of files. Unlike with system(), the command must be a string as the command shell is used for redirection and piping. The return value of system() is passed through, but reflects the success of the ptee command, which isn't very useful.

The second argument may be a hash-reference of options. Recognized options include:

  • stderr -- redirects STDERR to STDOUT before piping to ptee (default: false)

  • append -- passes the -a flag to ptee to append instead of overwriting (default: false)


Because of the way that Tee uses pipes, it is limited to capturing a single input stream, either STDOUT alone or both STDOUT and STDERR combined. A good, portable alternative for capturing these streams from a command separately is IPC::Run3, though it does not allow passing it through to a terminal at the same time.


  • ptee

  • IPC::Run3

  • IO::Tee


Please report any bugs or feature using the CPAN Request Tracker. Bugs can be submitted through the web interface at

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.


David Golden <>


This software is Copyright (c) 2006 by David Golden.

This is free software, licensed under:

  The Apache License, Version 2.0, January 2004