Overview: Env program

The Env program is intended for passing arguments and environment variables to started processes. When started, each process automatically sends a request to the Env process and receives the necessary data.

A process query to Env redefines the arguments and environment variables received through Einit.

To use the Env program in your solution, you need to do the following:

1. Develop the code of the Env program by using macros from env/env.h.

2. Build the binary file of the Env program by linking it to the env_server library.

3. In the init description, indicate that the Env process must be started and connected to the selected processes (Env acts a server in this case). The channel name is defined by the ENV_SERVICE_NAME macro declared in the env/env.h file.

4. Include the Env binary file in the solution image.

Env program code

The code of the Env program utilizes the following macros and functions declared in the env/env.h file:

• ENV_REGISTER_ARGS(name,argarr) – arguments from the argarr array are passed to the process named name (the maximum size of one element is 256 bytes).
• ENV_REGISTER_VARS(name,envarr) – environment variables from the envarr array are passed to the process named name (the maximum size of one element is 256 bytes).
• ENV_REGISTER_PROGRAM_ENVIRONMENT(name,argarr,envarr) – arguments and environment variables are passed to the process named name.
• envServerRun() – initialize the server part of the Env program so that it can respond to requests.

Env usage examples