From: Joel VanderWerf <vjoel@...>
Date: 2003-05-17T04:26:39+09:00
Subject: Re: p and perls Data::Dumper

Daniel Bretoi wrote:
> p is extremely usefl, for debugging etc.
> 
> Perl has it's equivalent with Data::Dumper
> 
> Another thing I've found useful, is that's easy to record a 
> data structure to a file, then read it back, and getting 
> the information using eval.
> 
> In perl, I would do 
> print FILEHANDLE Dumper %somehash
> 
> and I could easily read back everything in the hash.
> 
> Is ther eany way of recording the output of 'p' ?

Kernel#inspect returns the string that #p prints.

irb(main):001:0> x=[]
[]
irb(main):002:0> def x.inspect; "inspected!"; end
nil
irb(main):003:0> p x
inspected!
nil

But for user defined classes, the default #inspect string can't be read 
in as an object using eval.

irb(main):008:0> class Foo; end
nil
irb(main):009:0> p Foo.new
#<Foo:0x401f5b60>
nil
irb(main):010:0> eval Foo.new.inspect
nil

You may find AMarshal interesting, though:

http://raa.ruby-lang.org/list.rhtml?name=amarshal