SetEnvironfunction

Sets a system environment variable

Operating System Functionsfunctiondocumented

Syntax

Declare Function SetEnviron ( ByRef varexpression As String ) As Long

Parameters

Name		Description
`varexpression`		Name and setting of an environment variable in the following (or equivalent) form: varname=varstring. (varname being the name of the environment variable, and varstring being its text value to set)

Return value

Return zero (0) if successful, non-zero otherwise.

Description

Modifies system environment variables. There are several variables available for editing other than the default ones on your system. An example of this would be fbgfx, where you can choose the form of graphics driver the FreeBASIC graphics library will use.

Remarks

Usage



result = SetEnviron( varexpression )

Platform Differences

In Linux, varexpression must be permanent (a literal, a variable declared in the main code or a static variable declared in a procedure), because Linux does not memorize the string but only a pointer to its data characters.

Differences from QB

In QB, SetEnviron was called Environ.

Example

'e.g. to set the system variable "path" to "c:":



Shell "set path" 'shows the value of path

SetEnviron "path=c:"

Shell "set path" 'shows the new value of path

'' WINDOWS ONLY EXAMPLE! - We just set the graphics method to use

  '' GDI rather than DirectX (or Direct2D added on new systems).

  '' You may note a difference in FPS.

SetEnviron("fbgfx=GDI")



  '' Desktop width/height

Dim As Long ScrW, ScrH, BPP

ScreenInfo ScrW, ScrH, BPP



  '' Create a screen at the half width/height of your monitor.

  '' Normally this would be slow, but GDI is fairly fast for this kind

  '' of thing.

ScreenRes ScrW/2, ScrH/2, BPP



  '' Start our timer/

Dim As Double T = Timer



  '' Lock our page

ScreenLock

Do

  

    '' Print time since last frame

  Locate 1, 1

  Print "FPS: " & 1 / ( Timer - T )

  T = Timer

  

    '' Flip our screen

  ScreenUnlock

  ScreenLock

    '' Commit a graphical change to our screen.

  Cls

  

Loop Until Len(Inkey)



  '' unlock our page.

ScreenUnlock

Reference

Documented in KeyPgSetenviron.html