Running Custom Change Analyses¶
Dac-Man offers several ways for users to customize how change analyses are performed. An overview of these methods is given below.
Specifying custom analysis scripts via the command line¶
As we have seen in the Quickstart section, when comparing the contents of two files, Dac-Man's default behavior is to automatically select one of the available plug-ins to perform the comparison.
Dac-Man also allows users to use their own change analysis scripts instead of the available plug-ins,
by specifying the path to an executable with the --script option when invoking Dac-Man via the command-line interface:
dacman diff <file1> <file2> --script /path/to/myscript
For example, to use the Unix diff tool to compare all the modified files in the directories dir1 and dir2,
run the following command:
dacman diff /path/to/dir1 /path/to/dir2 --datachange --script /usr/bin/diff
The --datachange option tells to compare the data within the files of the two directories.
Example
An example showing how to use custom scripts for data change analysis can be found here.
Configuring plug-in selection for specific file types¶
The criteria used by Dac-Man to automatically select the plug-in to use for each file content comparison is based on the file type.
When Dac-Man is run for the first time, a plug-ins configuration file is created in the user's home directory,
under $HOME/.dacman/config/plugins.yaml.
Users can edit this file to override the default behavior and customize the selection of a plug-in for comparisons of specific file types.
The entries specified in the plugins.yaml file can refer to any of the plug-ins available within the Dac-Man plug-in framework.
All of the included plug-ins will be available once their dependencies (if any) have been installed.
For an overview of the included plug-ins, refer to the corresponding entry under the Plug-ins section.
For steps on installing dependencies for the build-in plug-ins, see here.
Developing a fully customized change analysis using custom plug-ins and the Dac-Man API¶
In addition to the included plug-in, users can also create and register their own plug-ins in Dac-Man. The Plug-in API section describes the Dac-Man plug-in API that can be used to create user-defined plug-ins in Dac-Man.
Finally, in addition to using the dacman command-line utility,
Dac-Man's Python API allows users to use Dac-Man's functionality within their own change analysis pipelines.
The API also provides the necessary module for users to specify a plug-in in their code.
Example
An example showing how to extend Dac-Man's included plug-ins, and use Dac-Man's API to incorporate them into custom analysis scripts can be found here.