replacing getenv/setenv on Windows - ticket 2636

[Jeffrey Altman]

SetEnvironmentVariable

Sets the contents of the specified environment variable for the current
process.


BOOL WINAPI SetEnvironmentVariable(
  LPCTSTR lpName,
  LPCTSTR lpValue
);

Parameters
lpName
[in] The name of the environment variable. The operating system creates
the environment variable if it does not exist and lpValue is not NULL.
lpValue
[in] The contents of the environment variable. The total size of the
environment block for a process may not exceed 32,767 characters. For
more information, see Environment Variables.
If this parameter is NULL, the variable is deleted from the current
process's environment.

Return Values
If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error
information, call GetLastError.

Remarks
This function has no effect on the system environment variables or the
environment variables of other processes.