SetEnvironmentVariable

The SetEnvironmentVariable function sets the value of an environment variable for the current process.

BOOL SetEnvironmentVariable(
  LPCTSTR lpName,  // environment variable name
  LPCTSTR lpValue  // new value for variable
);

Parameters

lpName

[in] Pointer to a null-terminated string that specifies the environment variable whose value is being set. The operating system creates the environment variable if it does not exist and lpValue is not NULL.

lpValue

[in] Pointer to a null-terminated string containing the new value of the specified environment variable. 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.

To add or modify system environment variables, the user selects System from the Control Panel, then selects the Environment tab. The user can also add or modify environment variables at a command prompt using the set command. Environment variables created with the set command apply only to the command window in which they are set, and to its child processes. For more information, type set /? at a command prompt.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Windows 95/98: Requires Windows 95 or later.
  Header: Declared in Winbase.h; include Windows.h.
  Library: Use Kernel32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT/2000.

See Also

Processes and Threads Overview, Process and Thread Functions, GetEnvironmentVariable