Setting OS Environment Variables

putenv() sets the program environment variables. How do you set the OS environment variables? I want to be able to set an environment variable that will stay after the program ends.

Thanks

What OS/compiler ?

16-bit DOS. I'm using the MARS 16 bit compiler.

Your help is appreciated.

Thanks

You could use 'system' with a SET command.

Code:

---

#include <stdio.h>
#include <stdlib.h>

int main ()
{
  int i;
  puts ("Trying to set environment variables");
  i = system ("SET BLASTER 220 5 1");
  if (i==-1) puts ("Error setting variables");
  else puts ("Environment variables set");
  return 0;
}

---

nb: Code blatently stolen and changed to fit your question.

> i = system ("SET BLASTER 220 5 1");
This creates a sub-process which gets an environment variable set for its very short existance and then all is lost again when the sub-process exits.

It is possible to 'hack' the parent environment in real DOS (not any win32 console, nor any POSIX operating system), but as I recall, that involved some rather tricky assembler work.