[rosmsg] Rosmsg info implemented as alias of rosmsg show

[javierdiazp]

All the other ros* commands use "info" to display their details, except rosmsg, which uses "show". In order to maintain consistency, the alias "rosmsg info" of "rosmsg show" was implemented.

[IanTheEngineer]

+1 for each time I accidentally typed rosmsg info in the past ... (a lot :)

[jfabry]

This is joint work of Javier with @OmniSliver (credit where credit is due) as part of a course I am teaching at U. Chile. They have a blog about their work (in Spanish) here: https://javierdiazp.github.io/robotica2/

[mikepurvis]

Possible alternative:

         if command in ('show', 'info'):
            sys.exit(rosmsg_cmd_show(ext, full, command))

[dirk-thomas]

@javierdiazp Can you please update the code with the suggestion from @mikepurvis

[mikepurvis]

This should target kinetic-devel. Otherwise LGTM.

[mikepurvis]

It needs to be manually cherry-picked due to the other branch changes. I'll do this now.

[mikepurvis]

@ros-pull-request-builder test this please

@dirk-thomas This is failing because Jenkins is triggering the indigo/jade jobs (which fail to merge) rather than kinetic. I believe it will pass though; my inclination is to just merge now and roll it back if there's a problem with the post-merge CI build.

[dirk-thomas]

@ros-pull-request-builder retest this please

[dirk-thomas]

Can you please create a related PR to add the completion for this new verb: https://github.com/ros/ros/blob/58acf513dfdc056f922666820ac24aa7d25ff521/tools/rosbash/rosbash#L882

[dirk-thomas]

@javierdiazp Can you please update the code with the suggestion from @mikepurvis

[dirk-thomas]

I would suggest keeping the existing line and adding a new line for the alias:

\t%(cmd)s show\tShow %(type_lower)s description
\t%(cmd)s info\tAlias for %(cmd)s show

[mikepurvis]

I've added a commit which addresses the review feedback, and the completion verb PR is at ros/ros#138.

[mikepurvis]

Output looks good:

$ rosmsg -h
rosmsg is a command-line tool for displaying information about ROS Message types.

Commands:
	rosmsg show	Show message description
	rosmsg info	Alias for rosmsg show
	rosmsg list	List all messages
	rosmsg md5	Display message md5sum
	rosmsg package	List messages in a package
	rosmsg packages	List packages that contain messages

Type rosmsg <command> -h for more detailed usage

$ rosmsg show -h
Usage: rosmsg show [options] <message type>

Options:
  -h, --help            show this help message and exit
  -r, --raw             show raw message text, including comments
  -b BAGFILE, --bag=BAGFILE
                        show message from .bag file

$ rosmsg info -h
Usage: rosmsg info [options] <message type>

Options:
  -h, --help            show this help message and exit
  -r, --raw             show raw message text, including comments
  -b BAGFILE, --bag=BAGFILE
                        show message from .bag file

$ rosmsg show Bool
[std_msgs/Bool]:
bool data

$ rosmsg info Bool
[std_msgs/Bool]:
bool data

Thanks for the contribution, @javierdiazp!