IO::Pager::Buffered(3) Pipe deferred output to PAGER if destination is a TTY


use IO::Pager::Buffered;
local $token = IO::Pager::Buffered::open *STDOUT;
print <<" HEREDOC" ;
A bunch of text later
# You can also use scalar filehandles...
my $token = IO::Pager::Buffered::open($FH) or warn($!);
print $FH "No globs or barewords for us thanks!\n";
# ...or an object interface
my $token = new IO::Pager::Buffered;
$token->print("OO shiny...\n");


IO::Pager subclasses are designed to programmatically decide whether or not to pipe a filehandle's output to a program specified in PAGER; determined and set by IO::Pager at runtime if not yet defined.

This subclass buffers all output for display upon exiting the current scope. If this is not what you want look at another subclass such as IO::Pager::Unbuffered. While probably not common, this may be useful in some cases,such as buffering all output to STDOUT while the process occurs, showing only warnings on STDERR, then displaying the output to STDOUT after. Or alternately letting output to STDOUT slide by and defer warnings for later perusal.


Class-specific method specifics below, others are inherited from IO::Pager.

open( [FILEHANDLE] )

Instantiate a new IO::Pager to paginate FILEHANDLE if necessary. Assign the return value to a scoped variable. Output does not occur until all references to this variable are destroyed eg; upon leaving the current scope. See ``DESCRIPTION''.


Almost identical to open, except that you will get an IO::Handle back if there's no TTY to allow for IO::Pager agnostic programming.


Returns the size of the buffer in bytes.


Immediately flushes the contents of the buffer.

If the last print did not end with a newline, the text from the preceding newline to the end of the buffer will be flushed but is unlikely to display until a newline is printed and flushed.


If you mix buffered and unbuffered operations the output order is unspecified, and will probably differ for a TTY vs. a file. See perlfunc.

$, is used see perlvar.


Jerrad Pierce <[email protected]>

Florent Angly <[email protected]>

This module was inspired by Monte Mitzelfelt's IO::Page 0.02


Copyright (C) 2003-2012 Jerrad Pierce
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This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.0 or, at your option, any later version of Perl 5 you may have available.