ros_introspection

ros_introspection is a library for looking at the files within a ROS package in a structured way.

You can specify the path directly.

from ros_introspection.package import Package
pkg = Package('/full/path/geometry_msgs')

or you can use the built-in crawler

from ros_introspection.util import get_packages

for package in get_packages('/home/dlu/catkin_work/src'):
    print(package)

If you want to look in the current folder, you don’t need to specify a folder to get_packages.

Package Structure

A package is path (where the $PATH/package.xml exists) and collection of sets of files.

• Key Metadata Files package.xml (a.k.a. the manifest), CMakeLists.txt and sometimes setup.py.
• Source Code Typical extensions: .py, .cpp, .h, .hpp, .c. Also things with a python hashbang.
• Generator Files Messages, services, and actions
• Launch Files
• Dynamic Reconfigure Configs cfg/*.cfg
• Plugin Configurations Usually a single xml file in the root.
• All Other Files Including robot models, data files, configuration files.

PackageXML

The manifest is

• a parsed XML dom
• a saved xml header/declaration
• an optional version number
• our guess of the standard tab size

CMakeLists.txt

This file is parsed into a series of Commands, CommandGroups and whitespace/comment strings. CommandGroups are mini CMake objects (groups of commands) surrounded by a pair of matching tags, like if/endif or foreach/endforeach.

Commands have the form command_name(sections*). Commands track their initial string representation to avoid needless formatting changes. Each Section is an optional initial section_name, followed by some number of tokens. Each Section also has a defined SectionStyle.

Source Code

The source code is a collection of individual source code files. Each file has a language variable as well as a set of tags. Right now, possible tags include

• library - C++ library file
• executable - C++ executable file
• test - Used only in tests

setup.py is not considered a source file.

Generator Files (Messages, services and actions)

These files are parsed to determine their package dependencies.

Launch Files

Launch files are parsed XML and are read-only. There is a flag for determining whether the launch file is for tests.

Dynamic Reconfigure Configs

These files are not parsed, and only their filename is stored.

Plugin Configurations

This XML configuration can be read and written depending on the needs of the pluginlib macro invocations.