QNX CAR environment variables

You can set environment variables specific to the QNX CAR platform in the app descriptor file. These settings define the app's display area and its resource paths on the target system.

The QNX CAR environment variables are:

QQNX_PHYSICAL_SCREEN_SIZE

(Required for all apps)

Defines the height and width of the app's display area on the screen. These values are specified in millimeters, not pixels. This is because QNX CAR requires a physical unit and not a virtual unit.

QNXCAR2_ASSETS_DIR

(Optional)

Specifies the path on the target system of any shared resources used by the app. You can share resources among many apps to reduce the sizes of individual apps; this is particularly useful for large resources (e.g., font files). Also, shared resources don't have to be packaged into the app's BAR file or compiled into its binary executable.

LD_LIBRARY_PATH

(Optional)

Specifies the path on the target system of any external libraries (i.e., libraries outside of the Qt framework) used by the app. All QNX Qt development libraries (e.g., QtQnxCar2) are located in /qtcar/lib/. You can install third-party libraries to this same location or to another location. In the latter case, you need to add the directory that stores these other libraries to the LD_LIBRARY_PATH variable, using a colon (:) to separate the different entries.

In the app descriptor file, environment variables are set using <env> tags, where the var attribute lists the variable's name and the value attribute lists its value. For instance, the following XML element sets the shared resources path:

<env var="QNXCAR2_ASSETS_DIR" value="qtcar/share"/>