Provided by: libdata-printer-perl_0.36-1_all bug

NAME

       Data::Printer - colored pretty-print of Perl data structures and objects

SYNOPSIS

       Want to see what's inside a variable in a complete, colored and human-friendly way?

         use Data::Printer;   # or just "use DDP" for short

         p @array;            # no need to pass references

       Code above might output something like this (with colors!):

          [
              [0] "a",
              [1] "b",
              [2] undef,
              [3] "c",
          ]

       You can also inspect objects:

           my $obj = SomeClass->new;

           p($obj);

       Which might give you something like:

         \ SomeClass  {
             Parents       Moose::Object
             Linear @ISA   SomeClass, Moose::Object
             public methods (3) : bar, foo, meta
             private methods (0)
             internals: {
                _something => 42,
             }
         }

       Data::Printer is fully customizable. If you want to change how things are displayed, or
       even its standard behavior. Take a look at the available customizations. Once you figure
       out your own preferences, create a configuration file for yourself and Data::Printer will
       automatically use it!

       That's about it! Feel free to stop reading now and start dumping your data structures! For
       more information, including feature set, how to create filters, and general tips, just
       keep reading :)

       Oh, if you are just experimenting and/or don't want to use a configuration file, you can
       set all options during initialization, including coloring, indentation and filters!

         use Data::Printer {
             color => {
                'regex' => 'blue',
                'hash'  => 'yellow',
             },
             filters => {
                'DateTime' => sub { $_[0]->ymd },
                'SCALAR'   => sub { "oh noes, I found a scalar! $_[0]" },
             },
         };

       The first "{}" block is just syntax sugar, you can safely omit it if it makes things
       easier to read:

         use DDP colored => 1;

         use Data::Printer  deparse => 1, sort_keys => 0;

FEATURES

       Here's what Data::Printer has to offer to Perl developers, out of the box:

       •   Very sane defaults (I hope!)

       •   Highly customizable (in case you disagree with me :)

       •   Colored output by default

       •   Human-friendly output, with array index and custom separators

       •   Full object dumps including methods, inheritance and internals

       •   Exposes extra information such as tainted data and weak references

       •   Ability to easily create filters for objects and regular structures

       •   Ability to load settings from a ".dataprinter" file so you don't have to write
           anything other than "use DDP;" in your code!

RATIONALE

       Data::Dumper is a fantastic tool, meant to stringify data structures in a way they are
       suitable for being "eval"'ed back in.

       The thing is, a lot of people keep using it (and similar ones, like Data::Dump) to print
       data structures and objects on screen for inspection and debugging, and while you can use
       those modules for that, it doesn't mean you should.

       This is where Data::Printer comes in. It is meant to do one thing and one thing only:

       display Perl variables and objects on screen, properly formatted (to be inspected by a
       human)

       If you want to serialize/store/restore Perl data structures, this module will NOT help
       you. Try Storable, Data::Dumper, JSON, or whatever. CPAN is full of such solutions!

THE p() FUNCTION

       Once you load Data::Printer, the "p()" function will be imported into your namespace and
       available to you. It will pretty-print into STDERR (or any other output target) whatever
       variable you pass to it.

   Changing output targets
       By default, "p()" will be set to use STDERR. As of version 0.27, you can set up the
       'output' property so Data::Printer outputs to several different places:

       •   "output => 'stderr'" - Standard error. Same as *STDERR

       •   "output => 'stdout'" - Standard output. Same as *STDOUT

       •   "output => $filename" - Appends to filename.

       •   "output => $file_handle" - Appends to opened handle

       •   "output => \$scalar" - Appends to that variable's content

   Return Value
       As of version 0.36, Data::Printer's return value defaults to "pass-through", meaning it
       will dump the variable to STDERR (or wherever you set the output to) and will return the
       variable itself.

       If for whatever reason you want to mangle with the output string instead of printing it,
       you can either use the (also exported) "np()" function which always returns the string to
       be printed:

           use DDP;

           # move to a string
           my $string = np @some_array;

           # send as a warning
           warn np($some_string);

           # output to STDOUT instead of STDERR
           print np(%some_hash);

       or change the return value to 'dump' and ask for p()'s return value instead: value:

         use DDP return_value => 'dump';

         # move to a string
         my $string = p @some_array;

         # output to STDOUT instead of STDERR;
         print p(%some_hash);

       Note that, in this case, Data::Printer will not colorize the returned string unless you
       explicitly set the "colored" option to 1:

         print p(%some_hash, colored => 1); # now with colors!

       You can - and should - of course, set this during you ""use"" call:

         use Data::Printer colored => 1;
         print p( %some_hash );  # will be colored

       Or by adding the setting to your ".dataprinter" file.

       As most of Data::Printer, the return value is also configurable. You do this by setting
       the "return_value" option. There are three options available:

       •   'dump'

               p %var;               # prints the dump to STDERR (void context)
               my $string = p %var;  # returns the dump *without* printing

       •   'void':

               p %var;               # prints the dump to STDERR, never returns.
               my $string = p %var;  # $string is undef. Data still printed in STDERR

       •   'pass' (default as of 0.36):

               p %var;               # prints the dump to STDERR, returns %var
               my %copy = p %var;    # %copy = %var. Data still printed in STDERR

COLORS AND COLORIZATION

       Below are all the available colorizations and their default values.  Note that both
       spellings ('color' and 'colour') will work.

          use Data::Printer {
            color => {
               array       => 'bright_white',  # array index numbers
               number      => 'bright_blue',   # numbers
               string      => 'bright_yellow', # strings
               class       => 'bright_green',  # class names
               method      => 'bright_green',  # method names
               undef       => 'bright_red',    # the 'undef' value
               hash        => 'magenta',       # hash keys
               regex       => 'yellow',        # regular expressions
               code        => 'green',         # code references
               glob        => 'bright_cyan',   # globs (usually file handles)
               vstring     => 'bright_blue',   # version strings (v5.16.0, etc)
               repeated    => 'white on_red',  # references to seen values
               caller_info => 'bright_cyan',   # details on what's being printed
               weak        => 'cyan',          # weak references
               tainted     => 'red',           # tainted content
               escaped     => 'bright_red',    # escaped characters (\t, \n, etc)

               # potential new Perl datatypes, unknown to Data::Printer
               unknown     => 'bright_yellow on_blue',
            },
          };

       Don't fancy colors? Disable them with:

         use Data::Printer colored => 0;

       By default, 'colored' is set to "auto", which means Data::Printer will colorize only when
       not being used to return the dump string, nor when the output (default: STDERR) is being
       piped. If you're not seeing colors, try forcing it with:

         use Data::Printer colored => 1;

       Also worth noticing that Data::Printer will honor the "ANSI_COLORS_DISABLED" environment
       variable unless you force a colored output by setting 'colored' to 1.

       Remember to put your preferred settings in the ".dataprinter" file so you never have to
       type them at all!

ALIASING

       Data::Printer provides the nice, short, "p()" function to dump your data structures and
       objects. In case you rather use a more explicit name, already have a "p()" function (why?)
       in your code and want to avoid clashing, or are just used to other function names for that
       purpose, you can easily rename it:

         use Data::Printer alias => 'Dumper';

         Dumper( %foo );

CUSTOMIZATION

       I tried to provide sane defaults for Data::Printer, so you'll never have to worry about
       anything other than typing "p( $var )" in your code.  That said, and besides coloring and
       filtering, there are several other customization options available, as shown below (with
       default values):

         use Data::Printer {
             name           => 'var',   # name to display on cyclic references
             indent         => 4,       # how many spaces in each indent
             hash_separator => '   ',   # what separates keys from values
             align_hash     => 1,       # align values in hash
             colored        => 'auto',  # colorize output (1 for always, 0 for never)
             index          => 1,       # display array indices
             multiline      => 1,       # display in multiple lines (see note below)
             max_depth      => 0,       # how deep to traverse the data (0 for all)
             sort_keys      => 1,       # sort hash keys
             deparse        => 0,       # use B::Deparse to expand (expose) subroutines
             show_tied      => 1,       # expose tied variables
             show_tainted   => 1,       # expose tainted variables
             show_weak      => 1,       # expose weak references
             show_readonly  => 0,       # expose scalar variables marked as read-only
             show_lvalue    => 1,       # expose lvalue types
             print_escapes  => 0,       # print non-printable chars as "\n", "\t", etc.
             escape_chars   => 'none',  # escape chars into \x{...} form.  Values are
                                        # "none", "nonascii", "nonlatin1", "all"
             quote_keys     => 'auto',  # quote hash keys (1 for always, 0 for never).
                                        # 'auto' will quote when key is empty/space-only.
             scalar_quotes  => '"',     # the quote symbols to enclose scalar values
             separator      => ',',     # uses ',' to separate array/hash elements
             end_separator  => 0,       # prints the separator after last element in array/hash.
                                        # the default is 0 that means not to print

             caller_info    => 0,       # include information on what's being printed
             use_prototypes => 1,       # allow p(%foo), but prevent anonymous data
             return_value   => 'dump',  # what should p() return? See 'Return Value' above.
             output         => 'stderr',# where to print the output. See
                                        # 'Changing output targets' above.

             class_method   => '_data_printer', # make classes aware of Data::Printer
                                                # and able to dump themselves.

             class => {
                 internals  => 1,       # show internal data structures of classes

                 inherited  => 'none',  # show inherited methods,
                                        # can also be 'all', 'private', or 'public'.

                 universal  => 1,       # include UNIVERSAL methods in inheritance list

                 parents    => 1,       # show parents, if there are any
                 linear_isa => 'auto',  # show the entire @ISA, linearized, whenever
                                        # the object has more than one parent. Can
                                        # also be set to 1 (always show) or 0 (never).

                 expand     => 1,       # how deep to traverse the object (in case
                                        # it contains other objects). Defaults to
                                        # 1, meaning expand only itself. Can be any
                                        # number, 0 for no class expansion, and 'all'
                                        # to expand everything.

                 sort_methods => 1,     # sort public and private methods

                 show_methods => 'all'  # method list. Also 'none', 'public', 'private'
             },
         };

       Note: setting "multiline" to 0 will also set "index" and "indent" to 0.

FILTERS

       Data::Printer offers you the ability to use filters to override any kind of data display.
       The filters are placed on a hash, where keys are the types - or class names - and values
       are anonymous subs that receive two arguments: the item itself as first parameter, and the
       properties hashref (in case your filter wants to read from it). This lets you quickly
       override the way Data::Printer handles and displays data types and, in particular,
       objects.

         use Data::Printer filters => {
                   'DateTime'      => sub { $_[0]->ymd },
                   'HTTP::Request' => sub { $_[0]->uri },
         };

       Perl types are named as "ref" calls them: SCALAR, ARRAY, HASH, REF, CODE, Regexp and GLOB.
       As for objects, just use the class' name, as shown above.

       As of version 0.13, you may also use the '-class' filter, which will be called for all
       non-perl types (objects).

       Your filters are supposed to return a defined value (usually, the string you want to
       print). If you don't, Data::Printer will let the next filter of that same type have a go,
       or just fallback to the defaults. You can also use an array reference to pass more than
       one filter for the same type or class.

       Note: If you plan on calling "p()" from within an inline filter, please make sure you are
       passing only REFERENCES as arguments. See "CAVEATS" below.

       You may also like to specify standalone filter modules. Please see Data::Printer::Filter
       for further information on a more powerful filter interface for Data::Printer, including
       useful filters that are shipped as part of this distribution.

MAKING YOUR CLASSES DDP-AWARE (WITHOUT ADDING ANY DEPS)

       Whenever printing the contents of a class, Data::Printer first checks to see if that class
       implements a sub called '_data_printer' (or whatever you set the "class_method" option to
       in your settings, see "CUSTOMIZATION" below).

       If a sub with that exact name is available in the target object, Data::Printer will use it
       to get the string to print instead of making a regular class dump.

       This means you could have the following in one of your classes:

         sub _data_printer {
             my ($self, $properties) = @_;
             return 'Hey, no peeking! But foo contains ' . $self->foo;
         }

       Notice you don't have to depend on Data::Printer at all, just write your sub and it will
       use that to pretty-print your objects.

       If you want to use colors and filter helpers, and still not add Data::Printer to your
       dependencies, remember you can import them during runtime:

         sub _data_printer {
             require Data::Printer::Filter;
             Data::Printer::Filter->import;

             # now we have 'indent', outdent', 'linebreak', 'p' and 'colored'
             my ($self, $properties) = @_;
             ...
         }

       Having a filter for that particular class will of course override this setting.

CONFIGURATION FILE (RUN CONTROL)

       Data::Printer tries to let you easily customize as much as possible regarding the
       visualization of your data structures and objects.  But we don't want you to keep
       repeating yourself every time you want to use it!

       To avoid this, you can simply create a file called ".dataprinter" in your home directory
       (usually "/home/username" in Linux), and put your configuration hash reference in there.

       This way, instead of doing something like:

          use Data::Printer {
            colour => {
               array => 'bright_blue',
            },
            filters => {
                'Catalyst::Request' => sub {
                    my $req = shift;
                    return "Cookies: " . p($req->cookies)
                },
            },
          };

       You can create a .dataprinter file that looks like this:

          {
            colour => {
               array => 'bright_blue',
            },
            filters => {
                'Catalyst::Request' => sub {
                    my $req = shift;
                    return "Cookies: " . p($req->cookies)
                },
            },
          };

       Note that all we did was remove the "use Data::Printer" bit when writing the
       ".dataprinter" file. From then on all you have to do while debugging scripts is:

         use Data::Printer;

       and it will load your custom settings every time :)

   Loading RC files in custom locations
       If your RC file is somewhere other than ".dataprinter" in your home dir, you can load
       whichever file you want via the 'rc_file' parameter:

         use Data::Printer rc_file => '/path/to/my/rcfile.conf';

       You can even set this to undef or to a non-existing file to disable your RC file at will.

       The RC file location can also be specified with the "DATAPRINTERRC" environment variable.
       Using "rc_file" in code will override the environment variable.

   RC File Security
       The ".dataprinter" RC file is nothing but a Perl hash that gets "eval"'d back into the
       code. This means that whatever is in your RC file WILL BE INTERPRETED BY PERL AT RUNTIME.
       This can be quite worrying if you're not the one in control of the RC file.

       For this reason, Data::Printer takes extra precaution before loading the file:

       •   The file has to be in your home directory unless you specifically point elsewhere via
           the '"rc_file"' property or the DATAPRINTERRC environment variable;

       •   The file must be a plain file, never a symbolic link, named pipe or socket;

       •   The file must be owned by you (i.e. the effective user id that ran the script using
           Data::Printer);

       •   The file must be read-only for everyone but your user.  This usually means permissions
           0644, 0640 or 0600 in Unix-like systems. THIS IS NOT CHECKED IN WIN32;

       •   The file will NOT be loaded in Taint mode, unless you specifically load Data::Printer
           with the 'allow_tainted' option set to true. And even if you do that, Data::Printer
           will still issue a warning before loading the file. But seriously, don't do that.

       Failure to comply with the security rules above will result in the RC file not being
       loaded (likely with a warning on what went wrong).

THE "DDP" PACKAGE ALIAS

       You're likely to add/remove Data::Printer from source code being developed and debugged
       all the time, and typing it might feel too long. Because of this, the 'DDP' package is
       provided as a shorter alias to Data::Printer:

          use DDP;
          p %some_var;

CALLER INFORMATION

       If you set caller_info to a true value, Data::Printer will prepend every call with an
       informational message. For example:

         use Data::Printer caller_info => 1;

         my $var = 42;
         p $var;

       will output something like:

         Printing in line 4 of myapp.pl:
         42

       The default message is 'Printing in line __LINE__ of __FILENAME__:'.  The special strings
       "__LINE__", "__FILENAME__" and "__PACKAGE__" will be interpolated into their according
       value so you can customize them at will:

         use Data::Printer
           caller_info => 1,
           caller_message => "Okay, __PACKAGE__, let's dance!"
           color => {
               caller_info => 'bright_red',
           };

       As shown above, you may also set a color for "caller_info" in your color hash. Default is
       cyan.

EXPERIMENTAL FEATURES

       The following are volatile parts of the API which are subject to change at any given
       version. Use them at your own risk.

   Local Configuration (experimental!)
       You can override global configurations by writing them as the second parameter for p().
       For example:

         p( %var, color => { hash => 'green' } );

   Filter classes
       As of Data::Printer 0.11, you can create complex filters as a separate module. Those can
       even be uploaded to CPAN and used by other people!  See Data::Printer::Filter for further
       information.

CAVEATS

       You can't pass more than one variable at a time.

          p($foo, $bar); # wrong
          p($foo);       # right
          p($bar);       # right

       The default mode is to use prototypes, in which you are supposed to pass variables, not
       anonymous structures:

          p( { foo => 'bar' } ); # wrong

          p %somehash;        # right
          p $hash_ref;        # also right

       To pass anonymous structures, set "use_prototypes" option to 0. But remember you'll have
       to pass your variables as references:

          use Data::Printer use_prototypes => 0;

          p( { foo => 'bar' } ); # was wrong, now is right.

          p( %foo  ); # was right, but fails without prototypes
          p( \%foo ); # do this instead

       If you are using inline filters, and calling p() (or whatever name you aliased it to) from
       inside those filters, you must pass the arguments to "p()" as a reference:

         use Data::Printer {
             filters => {
                 ARRAY => sub {
                     my $listref = shift;
                     my $string = '';
                     foreach my $item (@$listref) {
                         $string .= p( \$item );      # p( $item ) will not work!
                     }
                     return $string;
                 },
             },
         };

       This happens because your filter function is compiled before Data::Printer itself loads,
       so the filter does not see the function prototype. As a way to avoid unpleasant surprises,
       if you forget to pass a reference, Data::Printer will generate an exception for you with
       the following message:

           'When calling p() without prototypes, please pass arguments as references'

       Another way to avoid this is to use the much more complete Data::Printer::Filter interface
       for standalone filters.

EXTRA TIPS

   Circumventing prototypes
       The "p()" function uses prototypes by default, allowing you to say:

         p %var;

       instead of always having to pass references, like:

         p \%var;

       There are cases, however, where you may want to pass anonymous structures, like:

         p { foo => $bar };   # this blows up, don't use

       and because of prototypes, you can't. If this is your case, just set "use_prototypes"
       option to 0. Note, with this option, you will have to pass your variables as references:

         use Data::Printer use_prototypes => 0;

          p { foo => 'bar' }; # doesn't blow up anymore, works just fine.

          p %var;  # but now this blows up...
          p \%var; # ...so do this instead

          p [ $foo, $bar, \@baz ]; # this way you can even pass
                                   # several variables at once

       Versions prior to 0.17 don't have the "use_prototypes" option. If you're stuck in an older
       version you can write "&p()" instead of "p()" to circumvent prototypes and pass elements
       (including anonymous variables) as REFERENCES. This notation, however, requires enclosing
       parentheses:

         &p( { foo => $bar } );        # this is ok, use at will
         &p( \"DEBUGGING THIS BIT" );  # this works too

       Or you could just create a very simple wrapper function:

         sub pp { p @_ };

       And use it just as you use "p()".

   Minding the return value of p()
       (contributed by Matt S. Trout (mst))

       There is a reason why explicit return statements are recommended unless you know what
       you're doing. By default, Data::Printer's return value depends on how it was called. When
       not in void context, it returns the serialized form of the dump.

       It's tempting to trust your own p() calls with that approach, but if this is your last
       statement in a function, you should keep in mind your debugging code will behave
       differently depending on how your function was called!

       To prevent that, set the "return_value" property to either 'void' or 'pass'. You won't be
       able to retrieve the dumped string but, hey, who does that anyway :)

       Assuming you have set the pass-through ('pass') property in your ".dataprinter" file,
       another stunningly useful thing you can do with it is change code that says:

          return $obj->foo;

       with:

          use DDP;

          return p $obj->foo;

       You can even add it to chained calls if you wish to see the dump of a particular state,
       changing this:

          $obj->foo->bar->baz;

       to:

          $obj->foo->DDP::p->bar->baz

       And things will "Just Work".

   Using p() in some/all of your loaded modules
       (contributed by Matt S. Trout (mst))

       While debugging your software, you may want to use Data::Printer in some or all loaded
       modules and not bother having to load it in each and every one of them. To do this, in any
       module loaded by "myapp.pl", simply write:

         ::p( @myvar );  # note the '::' in front of p()

       Then call your program like:

         perl -MDDP myapp.pl

       This also has the great advantage that if you leave one p() call in by accident, it will
       fail without the -M, making it easier to spot :)

       If you really want to have p() imported into your loaded modules, use the next tip
       instead.

   Adding p() to all your loaded modules
       (contributed by Arpad Szasz)

       If you wish to automatically add Data::Printer's "p()" function to every loaded module in
       you app, you can do something like this to your main program:

           BEGIN {
               {
                   no strict 'refs';
                   require Data::Printer;
                   my $alias = 'p';
                   foreach my $package ( keys %main:: ) {
                       if ( $package =~ m/::$/ ) {
                           *{ $package . $alias } = \&Data::Printer::p;
                       }
                   }
               }
           }

       WARNING This will override all locally defined subroutines/methods that are named "p", if
       they exist, in every loaded module. If you already have a subroutine named '"p()"', be
       sure to change $alias to something custom.

       If you rather avoid namespace manipulation altogether, use the previous tip instead.

   Using Data::Printer from the Perl debugger
       (contributed by Arpad Szasz and Marcel Gruenauer (hanekomu))

       With DB::Pluggable, you can easily set the perl debugger to use Data::Printer to print
       variable information, replacing the debugger's standard "p()" function. All you have to do
       is add these lines to your ".perldb" file:

         use DB::Pluggable;
         DB::Pluggable->run_with_config( \'[DataPrinter]' );  # note the '\'

       Then call the perl debugger as you normally would:

         perl -d myapp.pl

       Now Data::Printer's "p()" command will be used instead of the debugger's!

       See perldebug for more information on how to use the perl debugger, and DB::Pluggable for
       extra functionality and other plugins.

       If you can't or don't wish to use DB::Pluggable, or simply want to keep the debugger's
       "p()" function and add an extended version using Data::Printer (let's call it "px()" for
       instance), you can add these lines to your ".perldb" file instead:

           $DB::alias{px} = 's/px/DB::px/';
           sub px {
               my $expr = shift;
               require Data::Printer;
               print Data::Printer::p($expr);
           }

       Now, inside the Perl debugger, you can pass as reference to "px" expressions to be dumped
       using Data::Printer.

   Using Data::Printer in a perl shell (REPL)
       Some people really enjoy using a REPL shell to quickly try Perl code. One of the most
       famous ones out there is Devel::REPL. If you use it, now you can also see its output with
       Data::Printer!

       Just install Devel::REPL::Plugin::DataPrinter and add the following line to your re.pl
       configuration file (usually ".re.pl/repl.rc" in your home dir):

         load_plugin('DataPrinter');

       The next time you run "re.pl", it should dump all your REPL using Data::Printer!

   Easily rendering Data::Printer's output as HTML
       To turn Data::Printer's output into HTML, you can do something like:

         use HTML::FromANSI;
         use Data::Printer;

         my $html_output = ansi2html( p($object, colored => 1) );

       In the example above, the $html_output variable contains the HTML escaped output of
       "p($object)", so you can print it for later inspection or render it (if it's a web app).

   Using Data::Printer with Template Toolkit
       (contributed by Stephen Thirlwall (sdt))

       If you use Template Toolkit and want to dump your variables using Data::Printer, install
       the Template::Plugin::DataPrinter module and load it in your template:

          [% USE DataPrinter %]

       The provided methods match those of "Template::Plugin::Dumper":

          ansi-colored dump of the data structure in "myvar":
          [% DataPrinter.dump( myvar ) %]

          html-formatted, colored dump of the same data structure:
          [% DataPrinter.dump_html( myvar ) %]

       The module allows several customization options, even letting you load it as a complete
       drop-in replacement for Template::Plugin::Dumper so you don't even have to change your
       previous templates!

   Unified interface for Data::Printer and other debug formatters
       (contributed by Kevin McGrath (catlgrep))

       If you are porting your code to use Data::Printer instead of Data::Dumper or similar, you
       can just replace:

         use Data::Dumper;

       with:

         use Data::Printer alias => 'Dumper';
         # use Data::Dumper;

       making sure to provide Data::Printer with the proper alias for the previous dumping
       function.

       If, however, you want a really unified approach where you can easily flip between
       debugging outputs, use Any::Renderer and its plugins, like Any::Renderer::Data::Printer.

   Printing stack traces with arguments expanded using Data::Printer
       (contributed by Sergey Aleynikov (randir))

       There are times where viewing the current state of a variable is not enough, and you
       want/need to see a full stack trace of a function call.

       The Devel::PrettyTrace module uses Data::Printer to provide you just that. It exports a
       "bt()" function that pretty-prints detailed information on each function in your stack,
       making it easier to spot any issues!

   Troubleshooting apps in real time without changing a single line of your code
       (contributed by Marcel Gruenauer (hanekomu))

       dip is a dynamic instrumentation framework for troubleshooting Perl programs, similar to
       DTrace <http://opensolaris.org/os/community/dtrace/>.  In a nutshell, "dip" lets you
       create probes for certain conditions in your application that, once met, will perform a
       specific action. Since it uses Aspect-oriented programming, it's very lightweight and you
       only pay for what you use.

       "dip" can be very useful since it allows you to debug your software without changing a
       single line of your original code. And Data::Printer comes bundled with it, so you can use
       the "p()" function to view your data structures too!

          # Print a stack trace every time the name is changed,
          # except when reading from the database.
          dip -e 'before { print longmess(p $_->{args}[1]) if $_->{args}[1] }
            call "MyObj::name" & !cflow("MyObj::read")' myapp.pl

       You can check you dip's own documentation for more information and options.

   Sample output for color fine-tuning
       (contributed by Yanick Champoux (yanick))

       The "examples/try_me.pl" file included in this distribution has a sample dump with a
       complex data structure to let you quickly test color schemes.

   creating fiddling filters
       (contributed by dirk)

       Sometimes, you may want to take advantage of Data::Printer's original dump, but add/change
       some of the original data to enhance your debugging ability.  Say, for example, you have
       an "HTTP::Response" object you want to print but the content is encoded. The basic
       approach, of course, would be to just dump the decoded content:

         use DDP filter {
           'HTTP::Response' => sub { p( \shift->decoded_content, %{shift} );
         };

       But what if you want to see the rest of the original object? Dumping it would be a no-go,
       because you would just recurse forever in your own filter.

       Never fear! When you create a filter in Data::Printer, you're not replacing the original
       one, you're just stacking yours on top of it. To forward your data to the original filter,
       all you have to do is return an undefined value. This means you can rewrite your
       "HTTP::Response" filter like so, if you want:

         use DDP filters => {
           'HTTP::Response' => sub {
             my ($res, $p) = @_;

             # been here before? Switch to original handler
             return if exists $res->{decoded_content};

             # first timer? Come on in!
             my $clone = $res->clone;
             $clone->{decoded_content} = $clone->decoded_content;
             return p($clone, %$p);
           }
         };

       And voila! Your fiddling filter now works like a charm :)

BUGS

       If you find any, please file a bug report.

SEE ALSO

       Data::Dumper

       Data::Dump

       Data::Dumper::Concise

       Data::Dump::Streamer

       Data::PrettyPrintObjects

       Data::TreeDumper

AUTHOR

       Breno G. de Oliveira "<garu at cpan.org>"

CONTRIBUTORS

       Many thanks to everyone that helped design and develop this module with patches, bug
       reports, wishlists, comments and tests. They are (alphabetically):

       •   Allan Whiteford

       •   Andreas Koenig

       •   Andy Bach

       •   Arpad Szasz

       •   brian d foy

       •   Chris Prather (perigrin)

       •   David Golden (xdg)

       •   David Raab

       •   Damien Krotkine (dams)

       •   Denis Howe

       •   Dotan Dimet

       •   Eden Cardim (edenc)

       •   Elliot Shank (elliotjs)

       •   Fernando Correa (SmokeMachine)

       •   Fitz Elliott

       •   Ivan Bessarabov (bessarabv)

       •   J Mash

       •   Jesse Luehrs (doy)

       •   Joel Berger (jberger)

       •   Kartik Thakore (kthakore)

       •   Kevin Dawson (bowtie)

       •   Kevin McGrath (catlgrep)

       •   Kip Hampton (ubu)

       •   Marcel Gruenauer (hanekomu)

       •   Mark Fowler (Trelane)

       •   Matt S. Trout (mst)

       •   Maxim Vuets

       •   Mike Doherty (doherty)

       •   Paul Evans (LeoNerd)

       •   PrzemysXaw WesoXek (jest)

       •   Rebecca Turner (iarna)

       •   Rob Hoelz (hoelzro)

       •   Sebastian Willing (Sewi)

       •   Sergey Aleynikov (randir)

       •   Stanislaw Pusep (syp)

       •   Stephen Thirlwall (sdt)

       •   sugyan

       •   Tatsuhiko Miyagawa (miyagawa)

       •   Tim Heaney (oylenshpeegul)

       •   Torsten Raudssus (Getty)

       •   Wesley Dal`Col (blabos)

       •   Yanick Champoux (yanick)

       If I missed your name, please drop me a line!

LICENSE AND COPYRIGHT

       Copyright 2011 Breno G. de Oliveira "<garu at cpan.org>". All rights reserved.

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

DISCLAIMER OF WARRANTY

       BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE,
       TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE
       COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF
       ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
       WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO
       THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE
       DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

       IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT
       HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY
       THE ABOVE LICENCE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL,
       INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
       SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR
       LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY
       OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
       SUCH DAMAGES.