Term::TtyRec::Plus(3pm) 				User Contributed Perl Documentation				   Term::TtyRec::Plus(3pm)

NAME

       Term::TtyRec::Plus - read a ttyrec

SYNOPSIS

       "Term::TtyRec::Plus" is a module that lets you read ttyrec files. The related module, Term::TtyRec is designed more for simple
       interactions. "Term::TtyRec::Plus" gives you more information and, using a callback, lets you munge the data block and timestamp. It will
       do all the subtle work of making sure timing is kept consistent, and of rebuilding each frame header.

	   use Term::TtyRec::Plus;
	   # complete (but simple) ttyrec playback script

	   foreach my $file (@ARGV) {
	     my $ttyrec = Term::TtyRec::Plus->new(infile => $file, time_threshold => 10);
	     while (my $frame_ref = $ttyrec->next_frame()) {
	       select undef, undef, undef, $frame_ref->{diff};
	       print $frame_ref->{data};
	     }
	   }

CONSTRUCTOR AND STARTUP

   new()
       Creates and returns a new "Term::TtyRec::Plus" object.

	   my $ttyrec = Term::TtyRec::Plus->new();

       Parameters

       Here are the parameters that "Term::TtyRec::Plus->new()" recognizes.

       infile
	   The input filename. A value of "-", which is the default, or "undef", means "STDIN".

       filehandle
	   The input filehandle. By default this is "undef"; if you have already opened the ttyrec then you can pass its filehandle to the
	   constructor. If both filehandle and infile are defined, filehandle is used.

       bzip2
	   Perform bzip2 decompression. By default this is "undef", which signals that bzip2 decompression should occur if and only if the
	   filename is available and it ends in ".bz2". Otherwise, you can force or forbid decompression by setting bzip2 to a true or false
	   value, respectively. After the call to new, this field will be set to either 1 if decompression is enabled or 0 if it is not.

       time_threshold
	   The maximum difference between two frames, in seconds. If "undef", which is the default, there is no enforced maximum. The second most
	   common value would be 10, which some ttyrec utilities (such as timettyrec) use.

       frame_filter
	   A callback, run for each frame before returning the frame to the user of "Term::TtyRec::Plus". This callback receives three arguments:
	   the frame text, the timestamp, and the timestamp of the previous frame. All three arguments are passed as scalar references. The
	   previous frame's timestamp is "undef" for the first frame. The return value is not currently looked at. If you modify the timestamp,
	   the module will make sure that change is noted and respected in further frame timestamps. Modifications to the previous frame's
	   timestamp are currently ignored.

	       sub halve_frame_time_and_stumblify {
		   my ($data_ref, $time_ref, $prev_ref) = @_;
		   $$time_ref = $$prev_ref + ($$time_ref - $$prev_ref) / 2
		       if defined $$prev_ref;
		   $$data_ref =~ s/Eidolos/Stumbly/g;
	       }

       State

       In addition to passing arguments, you can modify "Term::TtyRec::Plus"'s initial state, if you want to. This could be useful if you are
       chaining multiple ttyrecs together; you could pass a different initial frame. Support for such chaining might be added in a future version.

       frame
	   The initial frame number. Default 0.

       prev_timestamp
	   The previous frame's timestamp. Default "undef".

       accum_diff
	   The accumulated difference of all frames seen so far; see the section on "diffed_timestamp" in "next_frame()"'s return value. Default
	   0.

       relative_time
	   The time passed since the first frame. Default 0.

METHODS

   next_frame()
       "next_frame()" reads and processes the next frame in the ttyrec. It accepts no arguments. On EOF, it will return "undef". On malformed
       ttyrec input, it will die. If it cannot reconstruct the header of a frame (which might happen if the callback sets the timestamp to -1, for
       example), it will die. Otherwise, a hash reference is returned with the following fields set.

       data
	   The frame data, filtered through the callback. The original data block is not made available.

       orig_timestamp
	   The frame timestamp, straight out of the file.

       diffed_timestamp
	   The frame timestamp, with the accumulated difference of all of the previous frames applied to it. This is so consistent results are
	   given. For example, if your callback adds three seconds to frame 5's timestamp, then frame 6's diffed timestamp will take into account
	   those three seconds, so frame 6 happens three seconds later as well. So the net effect is frame 5 is extended by three seconds, and no
	   other frames' relatives times are affected.

       timestamp
	   The diffed timestamp, filtered through the callback.

       prev_timestamp
	   The previous frame's timestamp (after diffing and filtering; the originals are not made available).

       diff
	   The difference between the current frame's timestamp and the previous frame's timestamp. Yes, it is equivalent to "timestamp -
	   prev_timestamp", but it is provided for convenience. On the first frame it will be 0 (not "undef").

       orig_header
	   The 12-byte frame header, straight from the file.

       header
	   The 12-byte frame header, reconstructed from "data" and "timestamp" (so, after filtering, etc.).

       frame
	   The frame number, using 1-based indexing.

       relative_time
	   The time between the first frame's timestamp and the current frame's timestamp.

   grep()
       Returns the next frame that meets the specified criteria. "grep()" accepts arguments that are subroutines, regex, or strings; anything else
       is a fatal error. If you pass multiple arguments to "grep()", each one must be true. The subroutines receive the frame reference that is
       returned by "next_frame()". You can modify the frame, but do so cautiously.

	 my $next_jump_frame_ref = $t->grep("Where do you want to jump?", sub { $_[0]{data} !~ /Message History/});

   rewind()
       Rewinds the ttyrec to the first frame and resets state variables to their initial values. Note that if "filehandle" is not seekable (such
       as STDIN on some systems, or if bzip2 decompression is used), "rewind()" will die.

   infile()
       Returns the infile passed to the constructor. If a filehandle was passed, this will be "undef".

   filehandle()
       Returns the filehandle passed to the constructor, or if "infile" was used, a handle to "infile".

   bzip2()
       Returns 1 if bzip2 decompression has taken place, 0 if it has not.

   time_threshold()
       Returns the time threshold passed to the constructor. By default it is "undef".

   frame_filter()
       Returns the frame filter callback passed to the constructor. By default it is "sub { @_ }".

   frame()
       Returns the frame number of the most recently returned frame.

   prev_timestamp()
       Returns the timestamp of the most recently returned frame.

   relative_time()
       Returns the time so far since the first frame.

   accum_diff()
       Returns the total time difference between timestamps and filtered timestamps. "accum_diff" is added to each frame's timestamp before they
       are passed to the "frame_filter" callback.

AUTHOR

       Shawn M Moore, "sartak@gmail.com"

CAVEATS

       o   Ttyrecs are frame-based. If you are trying to modify a string that is broken across multiple frames, it will not work. Say you have a
	   ttyrec that prints "foo" in frame one and "bar" in frame two, both with the same timestamp. In a ttyrec player, it might look like
	   these are one frame (with data "foobar"), but it's not. There is no easy, complete way to add arbitrary substitutions; you would have
	   to write (or reuse) a terminal emulator.

       o   If you modify the data block, weird things could happen. This is especially true of escape-code-littered ttyrecs (such as those of
	   NetHack). For best results, pretend the data block is an executable file; changes are OK as long as you do not change the length of the
	   file. It really depends on the ttyrec though.

       o   If you modify the timestamp of a frame so that it is not in sequence with other frames, the behavior is undefined (it is up to the
	   client program). "Term::TtyRec::Plus" will not reorder the frames for you.

       o   bzip2 support is transparent, mostly. Unfortunately IO::Uncompress::Bunzip2 is rather slow. I took a lengthy (~4 hours), bzipped ttyrec
	   and ran a simple script on it, depending on the built-in bzip2 decompression. This took nearly four minutes. Using bunzip2 then the
	   same script took about four seconds. So when you can, do explicit bzip2 decompression. Or better yet, help out the guys working on
	   IO::Uncompress::Bunzip2. :)

COPYRIGHT &; LICENSE
       Copyright 2006-2009 Shawn M Moore, all rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.14.2							    2012-03-06						   Term::TtyRec::Plus(3pm)