How to use a common variable in multiple files in CAPL (How to replace extern) - capl

Question

I wanted to use a variable in 5 main CAN files. I have one include file common for all 5 CAN files. So I defined and declared the variable in this include file. But when I read the value of the variable from the main files I always get 0. Unfortunately Extern is not available in CAPL. So is there a way to do this.
Thanks.

Answer 1

If you use CAPL with CANoe you can create a database with the Vector CANdb++ Editor and declare an Environment-Variable in the database.
You Can access this variable in all your CAPL-files like this:
putValue(YourEnvironmentVariable,12); // Assigns the value 12 to the variable
Write("%d",getValue(YourEnvironmentVariable); //Prints 12
You can also declare an event that is thrown on change of the environment variable.
on envVar YourEnvironmentVariable{//do something...}

Answer 2

You can use System Variables for global access.
First you want to define a new namespace and a system variable in an include file global.cin:
/* global.cin */
on Start {
// define a namespace
sysDefineNamespace("myNamespace");
// define an integer system variable with starting, minimum and maximum value
sysDefineVariableInt("myNamespace", "mySysvar", 0, 0, 99);
}
By including global.cin in the main.can file you can then access the system variable using the corresponding CAPL functions:
/* main.can */
includes
{
#include "global.cin"
}
on Start {
// set system variable value
sysSetVariableInt("myNamespace", "mySysvar", 42));
// read system variable value
write("mySysvar: %d", sysGetVariableInt("myNamespace", "mySysvar"));
}
For data types other than integer there are corresponding CAPL functions in the naming-style of
sysDefineVariable<data-type>()
sysSetVariable<data-type>()
sysGetVariable<data-type>()
You can find additional information about accessing system variables via CAPL in the documentation of CANoe / CANalyzer under CAPL Functions -> System Variables CAPL Functions