IO::Wrap - phpMan

NAME
    IO::Wrap - wrap raw filehandles in IO::Handle interface

SYNOPSIS
       use IO::Wrap;

       ### Do stuff with any kind of filehandle (including a bare globref), or
       ### any kind of blessed object that responds to a print() message.
       ###
       sub do_stuff {
           my $fh = shift;

           ### At this point, we have no idea what the user gave us...
           ### a globref? a FileHandle? a scalar filehandle name?

           $fh = wraphandle($fh);

           ### At this point, we know we have an IO::Handle-like object!

           $fh->print("Hey there!");
           ...
       }

DESCRIPTION
    Let's say you want to write some code which does I/O, but you don't want
    to force the caller to provide you with a FileHandle or IO::Handle
    object. You want them to be able to say:

        do_stuff(\*STDOUT);
        do_stuff('STDERR');
        do_stuff($some_FileHandle_object);
        do_stuff($some_IO_Handle_object);

    And even:

        do_stuff($any_object_with_a_print_method);

    Sure, one way to do it is to force the caller to use tiehandle(). But
    that puts the burden on them. Another way to do it is to use IO::Wrap,
    which provides you with the following functions:

    wraphandle SCALAR
        This function will take a single argument, and "wrap" it based on
        what it seems to be...

        *   A raw scalar filehandle name, like "STDOUT" or "Class::HANDLE".
            In this case, the filehandle name is wrapped in an IO::Wrap
            object, which is returned.

        *   A raw filehandle glob, like "\*STDOUT". In this case, the
            filehandle glob is wrapped in an IO::Wrap object, which is
            returned.

        *   A blessed FileHandle object. In this case, the FileHandle is
            wrapped in an IO::Wrap object if and only if your FileHandle
            class does not support the "read()" method.

        *   Any other kind of blessed object, which is assumed to be already
            conformant to the IO::Handle interface. In this case, you just
            get back that object.

    If you get back an IO::Wrap object, it will obey a basic subset of the
    IO:: interface. That is, the following methods (note: I said *methods*,
    not named operators) should work on the thing you get back:

        close
        getline
        getlines
        print ARGS...
        read BUFFER,NBYTES
        seek POS,WHENCE
        tell

NOTES
    Clearly, when wrapping a raw external filehandle (like \*STDOUT), I
    didn't want to close the file descriptor when the "wrapper" object is
    destroyed... since the user might not appreciate that! Hence, there's no
    DESTROY method in this class.

    When wrapping a FileHandle object, however, I believe that Perl will
    invoke the FileHandle::DESTROY when the last reference goes away, so in
    that case, the filehandle is closed if the wrapped FileHandle really was
    the last reference to it.

WARNINGS
    This module does not allow you to wrap filehandle names which are given
    as strings that lack the package they were opened in. That is, if a user
    opens FOO in package Foo, they must pass it to you either as "\*FOO" or
    as "Foo::FOO". However, "STDIN" and friends will work just fine.

VERSION
    $Id: Wrap.pm,v 1.2 2005/02/10 21:21:53 dfs Exp $

AUTHOR
    Primary Maintainer
        Dianne Skoll (dfs AT roaringpenguin.com).

    Original Author
        Eryq (eryq AT zeegee.com). President, ZeeGee Software Inc
        (http://www.zeegee.com).

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