Device Bus Monitor

The HP webOS SDK, beginning with 2.0, comes with a tool - ls-monitor (luna service monitor) - that lets you see traffic going over the webOS service bus, similar to a network sniffer that lets you observe HTTP traffic.

You can run this tool from a device shell.

See webOS Service APIs for a list of services available to 3rd party apps.

Another useful tool for testing services is luna-send, which lets you access services at a device command-line.

Usage 

ls-monitor [OPTION...]

Options 

Help Options:
  -?, --help                    Show help options

Application Options:
  -f, --filter=com.palm.foo     Filter by service name (or unique name)
  -l, --list                    List all entities (apps) connected to the hub
  -d, --debug                   Print extra output for debugging monitor but with UNBOUNDED MEMORY GROWTH

Usage Notes

With no switch, ls-monitor runs in monitor mode and outputs requests and responses to and from services.

The -l option returns a list of apps connected to the bus.

There are two system buses:

  1. Public bus - Used for all 3rd party apps.

  2. Private bus - Lists more services than the public bus, services that have access to sensitive systems.

Though the list shows service names and processes, not all of them actually accept incoming connections. Connecting to the bus is a two-way interface, so this also shows apps that just have an active subscription.

The -f option allows you to filter on requests to and from a particular service. Alternatively, you could pipe the output through tools like grep to do more sophisticated searches.

Example

A typical output line from ls-monitor might look like this: 

6663.549    [PRV]   return  41     com.palm.hidd (/var/run/ls2/VDVKHT)     (/var/run/ls2/GnoMz4)  {"returnValue":true}