DAP was created to transform text-based data on the command-line, specializing in transforms that are annoying or difficult to do with existing tools.

DAP reads data using an input plugin, transforms it through a series of filters, and prints it out again using an output plugin. Every record is treated as a document (aka: hash/dict) and filters are used to reduce, expand, and transform these documents as they pass through. Think of DAP as a mashup between sed, awk, grep, csvtool, and jq, with map/reduce capabilities.

DAP was written to process terabyte-sized public scan datasets, such as those provided by https://scans.io/. Although DAP isn't particularly fast, it can be used across multiple cores (and machines) by splitting the input source and wrapping the execution with GNU Parallel.

DAP requires Ruby, and is best suited for systems with a relatively current version with 2.1.0 being the minimum requirement. Ideally, this will be managed with either rbenv or rvm with the bundler gem also installed and up to date. Using system managed/installed Rubies is possible but fraught with peril.

DAP depends on Maxmind's geoip database to be able to append geographic metadata to analyzed datasets. If you intend on using this capability, run the following as root:

sudo mkdir -p /var/lib/geoip && cd /var/lib/geoip && sudo wget http://geolite.maxmind.com/download/geoip/database/GeoLiteCity.dat.gz && sudo gunzip GeoLiteCity.dat.gz && sudo mv GeoLiteCity.dat geoip.dat && sudo wget http://geolite.maxmind.com/download/geoip/database/asnum/GeoIPASNum.dat.gz && sudo gunzip GeoIPASNum.dat.gz

sudo apt-get install libgeoip-dev zlib1g-dev ruby ruby-dev gcc make ruby-bundler
gem install dap

brew update
brew install geoip
gem install dap

In its simplest form, DAP takes input, applies zero or more filters which modify the input, and then outputs the result. The input, filters and output are separated by plus signs (+). As seen from dap -h:

Uage: dap  [input] + [filter] + [output]
       --inputs
       --outputs
       --filters

To see which input/output formats are supported and what filters are available, run dap --inputs,dap --outputs or dap --filters, respectively.

This example reads as input a single IP address from STDIN in line form, applies geo-ip transofmrations as a filter on that line, and then returns the output as JSON:

$  echo 8.8.8.8 | bin/dap + lines + geo_ip line + json
{"line":"8.8.8.8","line.country_code":"US","line.country_code3":"USA","line.country_name":"United States","line.latitude":"38.0","line.longitude":"-97.0"}

This example does the same, but only outputs the geo-ip country code:

$  echo 8.8.8.8 | bin/dap + lines + geo_ip line + select line.country_code3 + lines
USA

There are also several examples of how to use DAP along with sample datasets here.