# phpman > man > Filter::tee(3pm)

## NAME
    [Filter::tee](https://www.chedong.com/phpMan.php/perldoc/Filter%3A%3Atee/markdown) - tee source filter

## SYNOPSIS
        use [Filter::tee](https://www.chedong.com/phpMan.php/perldoc/Filter%3A%3Atee/markdown) 'filename' ;
        use [Filter::tee](https://www.chedong.com/phpMan.php/perldoc/Filter%3A%3Atee/markdown) '>filename' ;
        use [Filter::tee](https://www.chedong.com/phpMan.php/perldoc/Filter%3A%3Atee/markdown) '>>filename' ;

## DESCRIPTION
    This filter copies all text from the line after the "use" in the current source file to the file
    specified by the parameter "filename".

    By default and when the filename is prefixed with a '>' the output file will be emptied first if
    it already exists.

    If the output filename is prefixed with '>>' it will be opened for appending.

    This filter is useful as a debugging aid when developing other source filters.

## AUTHOR
    Paul Marquess

## DATE
    20th June 1995.