[libcamera-devel] [PATCH] cam: Allow selecting cameras by index

[Laurent Pinchart]

Hi Niklas,

On Tue, Jun 18, 2019 at 09:44:42AM +0200, Niklas Söderlund wrote:
> On 2019-06-17 13:09:10 +0300, Laurent Pinchart wrote:
> > As camera names can be cumbersome to type, selection of cameras by index
> > from a list can be useful. Print the list of detected cameras with an
> > index for each item, and interpret the camera name as an index if it is
> > a numerical value in the range from 1 to the number of cameras.
> 
> I think you should also update the usage information for --camera to 
> indicate both camera name and index can be used to select a camera.

Good point ! Would the following be enough ?

        parser.addOption(OptCamera, OptionString,
-                        "Specify which camera to operate on", "camera",
+                        "Specify which camera to operate on, by name or by index", "camera",
                         ArgumentRequired, "camera");

> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> >  src/cam/main.cpp | 17 ++++++++++++++---
> >  1 file changed, 14 insertions(+), 3 deletions(-)
> > 
> > diff --git a/src/cam/main.cpp b/src/cam/main.cpp
> > index f03a9faf87fa..0e7610b1befd 100644
> > --- a/src/cam/main.cpp
> > +++ b/src/cam/main.cpp
> > @@ -73,7 +73,14 @@ int CamApp::init(int argc, char **argv)
> >  	}
> >  
> >  	if (options_.isSet(OptCamera)) {
> > -		camera_ = cm_->get(options_[OptCamera]);
> > +		const std::string &cameraName = options_[OptCamera];
> > +		char *endptr;
> > +		unsigned long index = strtoul(cameraName.c_str(), &endptr, 10);
> > +		if (*endptr == '\0' && index > 0 && index <= cm_->cameras().size())
> > +			camera_ = cm_->cameras()[index - 1];
> > +		else
> > +			camera_ = cm_->get(cameraName);
> > +
> >  		if (!camera_) {
> >  			std::cout << "Camera "
> >  				  << std::string(options_[OptCamera])
> > @@ -172,8 +179,12 @@ int CamApp::run()
> >  {
> >  	if (options_.isSet(OptList)) {
> >  		std::cout << "Available cameras:" << std::endl;
> > -		for (const std::shared_ptr<Camera> &cam : cm_->cameras())
> > -			std::cout << "- " << cam->name() << std::endl;
> > +
> > +		unsigned int index = 1;
> > +		for (const std::shared_ptr<Camera> &cam : cm_->cameras()) {
> > +			std::cout << index << ": " << cam->name() << std::endl;
> > +			index++;
> > +		}
> >  	}
> >  
> >  	if (options_.isSet(OptCapture)) {

-- 
Regards,

Laurent Pinchart