Apache Felix Gogo

Apache Felix Gogo is a subproject of Apache Felix implementing a command line shell for OSGi. It is used in many OSGi runtimes and servers (Felix distro, Eclipse IDE, Apache Karaf, …​).

Overview

The Gogo subproject consists of three bundles:

  • runtime - implements the core command processing functionality.

  • command - implements a set of basic commands.

  • jline - Advanced textual user interface with features like completion and colors

  • shell - provides a simple textual user interface to interact with the command processor.

Working with the sources

You can find the sources on apache svn there is also a mirror at github.

Clone git clone https://github.com/apache/felix

Build cd gogo mvn clean install

Using Gogo with the Felix Framework

Gogo is included as the default shell in the felix framework distribution. To use it, you just start the framework like normal:

$ java -jar bin/felix.jar
_______________
Welcome to Apache Felix Gogo

g!

Gogo shell integration in the framework distribution is also discussed in the framework usage document

Built in shell features

  • TAB

    Completion for commands and parameters

  • Cursor left, Cursor right

    Edit inside current line

  • Cursor up, Cursor down

    Scroll through history

  • Ctrl-C

    Interrupt execution of current command

  • Ctrl-D

    Exit the shell

  • Ctrl-R

    Search in history

  • [command1]

    [command2]

    Pipe output of command1 as input of command2

Basic commands

  • cat [URI]

    Read URI and print to stdout

  • cd [path]

    Change working directory

  • diag [bundleid]

    Shows why a bundle is not working

  • help

    Show the available commands

  • help [command]

    Shows detailed help about a command

  • head [bundleid]

    Print bundle headers

  • history

    Shows the history of executed commands

  • inspect capability service [bundleid]

    Lists all services provided by a bundle

  • inspect requirement service [bundleid]

    Lists all services required by a bundle

  • install [URI]

    Install a bundle from file or URI

  • lb

    List bundles

  • [command1]

    less

    Show output of command1 in a paged view

  • less [file]

    Show file in a paged view

  • ls [directory]

    Show directory contents

  • start [bundleid]

    Start the given bundle

  • stop [bundleid]

    Stop the given bundle

  • tac

    Capture stdin as string and optionally write to file

  • tail [file]

    Shows the last lines of a file. Using -f allows to follow the file changes.

  • uninstall [bundleid]

    Uninstall given bundle

Changing shell colors

The colors of the command shell cane be adjusted by setting a property in an init script or directly on the shell.

HIGHLIGHTER_COLORS = "rs=35:st=32:nu=32:co=32:va=36:vn=36:fu=94:bf=91:re=90"

The property above forms a map from highlight type to ANSI color code.

These are the highlight types

  • rs : Reserved words

  • st : Strings

  • nu : Numbers

  • co : Constants

  • va : Variable

  • vn : Variable name

  • fu : Function

  • bf : Bad function

  • un : Unknown

  • re : Repair

The colors of the ls output can be adjusted using

LS_COLORS = "dr=1;91:ex=1;92:sl=1;96:ot=34;43"

The color types are these:

  • dr : Directory

  • ex : Executable

  • sl : Symbolic Link

  • ot : Other

Last but not least grep can also be adjusted

GREP_COLORS = "mt=1;31:fn=35:ln=32:se=36"

Types:

  • mt : Hits in the text (sets both ms and mc)

  • ms : Matching text in selected line

  • mc : Matching text in context line

  • fn : File names

  • ln : Line numbers

  • se : Selected lines

  • sl : Whole selected line

  • cx : Context lines

  • rv : If set and match is inverted, the meaning of sl and cx is inverted

Origin in RFC 147

Gogo is based on the OSGi RFC 147, which describes a standard shell for OSGi-based environments. See RFC 147 Overview for more information. Unfortunately this RFC was never made a standard.