Sprad has asked for the wisdom of the Perl Monks concerning the following question:

I've written a simple Perl implementation of tee. I'd like to use it in a larger script to log STDERR to a file. Is it possible to put my tee code inside the main script as a function and pipe to it, or do I have to have it in a separate file?

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A fair fight is a sign of poor planning.

Replies are listed 'Best First'.
Re: Open pipe to a function?
by Roy Johnson (Monsignor) on Dec 10, 2003 at 21:48 UTC
    Have you looked at IO::Tee?
    The PerlMonk tr/// Advocate
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Re: Open pipe to a function?
by hardburn (Abbot) on Dec 10, 2003 at 21:44 UTC

    I'd like to use it in a larger script to log STDERR to a file.

    You don't need a seperate program for doing that. You can just reopen STDERR to wherever you like:

    open(STDERR, '>', '/path/to/logfile') 
    or die "Can't open STDERR to /path/to/logfile: $!\n";

    [download]

    ----
    I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
    -- Schemer

    : () { :|:& };:

    Note: All code is untested, unless otherwise stated

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Re: Open pipe to a function?
by tcf22 (Priest) on Dec 10, 2003 at 21:41 UTC
    If you are going to pipe it to a script, then I believe it has to be in another script.

    If all you need to do is write STDERR to a file, why not just do this at the beginning of your script: 
    open(STDERR, '>error.txt');

    [download]
    Update:Try using IO::Tee, like suggested by Roy Johnson. I included a sample in my reply to you below.

    - Tom

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      I can't just redirect it, because I also want to see it at runtime.

      ---
      A fair fight is a sign of poor planning.

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        You could probably do some tricks with IO::Multiplex. Just save the orginal filehandle like this:

        my $old_stderr = *STDERR;

        [download]

        And then reopen STDERR with IO::Multiplex with $old_stderr and a filehandle to the log file.

        ----
        I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
        -- Schemer

        : () { :|:& };:

        Note: All code is untested, unless otherwise stated

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        How about 
        use IO::Tee;
open(ERRLOG, '>error.txt');
my $tee = new IO::Tee(\*STDOUT, \*ERRLOG);
*STDERR = $tee;

        [download]

        - Tom

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