You could also use:

<param name="robot_description"
textfile="$(find learning_urdf)/my_urdf.xml" />

http://www.ros.org/wiki/roslaunch/XML/param

Kevin

On Fri, Apr 30, 2010 at 6:09 AM, Adam Stambler <adasta@gmail.com> wrote:

> Hi,
>
> You need parenthesis around your find command.  the $( ..) triggers an
> escape for the launch file interpreter and tells it to execute the
> commands inside.  It should look something like this:
>
> <param name="robot_description"
>  command="cat $(find learning_urdf)/my_urdf.xml" />
>
> Good luck,
> Adam
>
> On Fri, Apr 30, 2010 at 4:13 AM, shayan sengupta <shayanfennec@gmail.com>
> wrote:
> >
> > hi
> >
> > I have created an urdf package for my robot refering the urdf tutorials
> and its working as expected.I have included a visual tag to the top link of
> my robot so that i can visualize it on rviz.I tried creating a launch file
> using following set of instruction
> >
> > <launch>
> > <param name="robot_description" command="cat $(find
> packagename)/model.xml" />
> >
> > </launch>
> >
> > but when i try to launch this file i get invalid parameter tag error
> >
> >
> > Invalid <param> tag: Cannot load command parameter [my_urdf.xml]: command
> [cat $learning_urdf/my_urdf.xml] returned with code [1].
> >
> > Param xml is <param command="cat $learning_urdf/my_urdf.xml"
> name="my_urdf.xml"/>
> >
> >
> > Actually I am not quite sure what give as a parameter name.
> >
> > so if any one can suggest it would be a great help.
> >
> > Regards,
> > Shayan Sengupta
> >
> >
> >
> >
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> > ros-users@code.ros.org
> > https://code.ros.org/mailman/listinfo/ros-users
> >
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