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Data::Dump(3)         User Contributed Perl Documentation        Data::Dump(3)
NAME
       Data::Dump - Pretty printing of data structures
SYNOPSIS
        use Data::Dump qw(dump);
        $str = dump(@list);
        @copy_of_list = eval $str;
        # or use it for easy debug printout
        use Data::Dump; dd localtime;
DESCRIPTION
       This module provide a few functions that traverse their argument and
       produces a string as its result.  The string contains Perl code that,
       when "eval"ed, produces a deep copy of the original arguments.
       The main feature of the module is that it strives to produce output
       that is easy to read.  Example:
           @a = (1, [2, 3], {4 => 5});
           dump(@a);
       Produces:
           "(1, [2, 3], { 4 => 5 })"
       If you dump just a little data, it is output on a single line. If you
       dump data that is more complex or there is a lot of it, line breaks are
       automatically added to keep it easy to read.
       The following functions are provided (only the dd* functions are
       exported by default):
       dump( ... )
       pp( ... )
           Returns a string containing a Perl expression.  If you pass this
           string to Perl's built-in eval() function it should return a copy
           of the arguments you passed to dump().
           If you call the function with multiple arguments then the output
           will be wrapped in parenthesis "( ..., ... )".  If you call the
           function with a single argument the output will not have the
           wrapping.  If you call the function with a single scalar (non-
           reference) argument it will just return the scalar quoted if
           needed, but never break it into multiple lines.  If you pass
           multiple arguments or references to arrays of hashes then the
           return value might contain line breaks to format it for easier
           reading.  The returned string will never be "\n" terminated, even
           if contains multiple lines.  This allows code like this to place
           the semicolon in the expected place:
              print '$obj = ', dump($obj), ";\n";
           If dump() is called in void context, then the dump is printed on
           STDERR and then "\n" terminated.  You might find this useful for
           quick debug printouts, but the dd*() functions might be better
           alternatives for this.
           There is no difference between dump() and pp(), except that dump()
           shares its name with a not-so-useful perl builtin.  Because of this
           some might want to avoid using that name.
       quote( $string )
           Returns a quoted version of the provided string.
           It differs from "dump($string)" in that it will quote even numbers
           and not try to come up with clever expressions that might shorten
           the output.  If a non-scalar argument is provided then it's just
           stringified instead of traversed.
       dd( ... )
       ddx( ... )
           These functions will call dump() on their argument and print the
           result to STDOUT (actually, it's the currently selected output
           handle, but STDOUT is the default for that).
           The difference between them is only that ddx() will prefix the
           lines it prints with "# " and mark the first line with the file and
           line number where it was called.  This is meant to be useful for
           debug printouts of state within programs.
       dumpf( ..., \&filter )
           Short hand for calling the dump_filtered() function of
           Data::Dump::Filtered.  This works like dump(), but the last
           argument should be a filter callback function.  As objects are
           visited the filter callback is invoked and it can modify how the
           objects are dumped.
CONFIGURATION
       There are a few global variables that can be set to modify the output
       generated by the dump functions.  It's wise to localize the setting of
       these.
       $Data::Dump::INDENT
           This holds the string that's used for indenting multiline data
           structures.  It's default value is "  " (two spaces).  Set it to ""
           to suppress indentation.  Setting it to "| " makes for nice visuals
           even if the dump output then fails to be valid Perl.
       $Data::Dump::TRY_BASE64
           How long must a binary string be before we try to use the base64
           encoding for the dump output.  The default is 50.  Set it to 0 to
           disable base64 dumps.
LIMITATIONS
       Code references will be dumped as "sub { ... }". Thus, "eval"ing them
       will not reproduce the original routine.  The "..."-operator used will
       also require perl-5.12 or better to be evaled.
       If you forget to explicitly import the "dump" function, your code will
       core dump. That's because you just called the builtin "dump" function
       by accident, which intentionally dumps core.  Because of this you can
       also import the same function as "pp", mnemonic for "pretty-print".
HISTORY
       The "Data::Dump" module grew out of frustration with Sarathy's in-most-
       cases-excellent "Data::Dumper".  Basic ideas and some code are shared
       with Sarathy's module.
       The "Data::Dump" module provides a much simpler interface than
       "Data::Dumper".  No OO interface is available and there are fewer
       configuration options to worry about.  The other benefit is that the
       dump produced does not try to set any variables.  It only returns what
       is needed to produce a copy of the arguments.  This means that
       "dump("foo")" simply returns '"foo"', and "dump(1..3)" simply returns
       '(1, 2, 3)'.
SEE ALSO
       Data::Dump::Filtered, Data::Dump::Trace, Data::Dumper, JSON, Storable
AUTHORS
       The "Data::Dump" module is written by Gisle Aas <gisle AT aas.no>, based
       on "Data::Dumper" by Gurusamy Sarathy <gsar AT umich.edu>.
        Copyright 1998-2010 Gisle Aas.
        Copyright 1996-1998 Gurusamy Sarathy.
       This library is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.
perl v5.26.3                      2015-06-09                     Data::Dump(3)