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Data::Printer::Filter::ContentType - detect popular (binary) content in strings


In your .dataprinter file:

    filters = ContentType

You may also customize the look and feel with the following options (defaults shown):

    filter_contenttype.show_size = 1
    filter_contenttype.size_unit = auto

    # play around with these if you want to print the binary content:
    filter_contenttype.hexdump        = 0
    filter_contenttype.hexdump_size   = 0
    filter_contenttype.hexdump_offset = 0
    filter_contenttype.hexdump_indent = 0

    # you can even customize your themes:
    colors.filter_contenttype         = #ca88dd
    colors.filter_contenttype_hexdump = #ffcb68

That's it!


This is a filter plugin for Data::Printer that looks for binary strings with signatures from popular file types. If one is detected, instead of the bogus binary dump it will print the content type and the string size.

For example, let's say you've read an image file into $data, maybe from a user upload or from Imager or ImageMagick. If you use Data::Printer with this filter, it will show you something like this:

    my $data = get_image_content_from_somewhere();

    use DDP; p $data;   # (PNG Image, 32K)


If, for whatever reason, you want to inspect the actual content of the binary data, you may set filter_contenttype.hexdump to true. This will pretty-print your data in hexadecimal, similar to tools like hexdump. Once active, it will print the entire content, but you may limit the size by changing filter_contenttype.hexdump_size to any value (unit == bytes), and you can even start from a different position using filter_contenttype.hexdump_offset. Set it to a negative value to make your offset relative to the end to the data.

Finally, the default hexdump mode will not indent your content. Since it's a binary dump, we want to get as much terminal space as we can. If you rather have the dump properly indented (relative to your current dump indentation level), just set filter_contenttype.hexdump_indent to 1.

Detected Content

Below are the signatures detected by this filter.


  • PNG

  • JPEG

  • GIF

  • ICO

  • TIFF

  • BMP


  • AVI

  • MPEG


  • WAV

  • MP3

  • FLAC

  • OGG

Documents and Archives

  • ZIP

  • GZIP

  • BZIP2

  • PDF

  • Binary Executables (ELF and Win32)

We don't want this list to grow into a full-blown detection system, and instead just focus on common types. So if you want to contribute with patches or open an issue for a missing type, please make sure you actually have data structures with that content (e.g. you were bit by this in your code and DDP didn't help).

We want to help people debug code, not add content types just for the sake of it :)