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IO::Wrap(3)	      User Contributed Perl Documentation	   IO::Wrap(3)

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...

	   o   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.

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

	   o   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.

	   o   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@roaringpenguin.com).

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

POD ERRORS
       Hey! The	above document had some	coding errors, which are explained
       below:

       Around line 218:
	   '=item' outside of any '=over'

	   =over without closing =back

perl v5.24.1			  2015-04-22			   IO::Wrap(3)

NAME | SYNOPSIS | DESCRIPTION | NOTES | WARNINGS | VERSION | AUTHOR | POD ERRORS

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