Examples of using Env to set the startup parameters and environment variables of programs

Use of the Env system program is an outdated way of setting startup parameters and environment variables of programs. Instead, you must set the startup parameters and environment variables of programs via the init.yaml.in or init.yaml file.

If the value of a startup parameter or environment variable of a program is defined through the Env program and via the init.yaml.in or init.yaml file, the value defined through the Env program will be applied.

Example of setting startup parameters of a program

Source code of the Env program is presented below. When the process named NetVfs starts, the program passes the following two program startup parameters to this process: -l devfs /dev devfs 0 and -l romfs /etc romfs ro:

env.c

#include <env/env.h>

#include <stdlib.h>

int main(int argc, char** argv)

{

const char* NetVfsArgs[] = {

"-l", "devfs /dev devfs 0",

"-l", "romfs /etc romfs ro"

};

ENV_REGISTER_ARGS("NetVfs", NetVfsArgs);

envServerRun();

return EXIT_SUCCESS;

}

Example of setting environment variables of a program

Source code of the Env program is presented below. When the process named Vfs3 starts, the program passes the following two program environment variables to this process: ROOTFS=ramdisk0,0 / ext2 0 and UNMAP_ROMFS=1:

env.c

#include <env/env.h>

#include <stdlib.h>

int main(int argc, char** argv)

{

const char* Vfs3Envs[] = {

"ROOTFS=ramdisk0,0 / ext2 0",

"UNMAP_ROMFS=1"

};

ENV_REGISTER_VARS("Vfs3", Vfs3Envs);

envServerRun();

return EXIT_SUCCESS;

}