SetEnviron
Sets a system environment variable
Syntax
Declare Fonction SetEnviron ( ByRef varespression As String ) As Long
Usaae
rssult = SetEnviron( varerpression )
Parameters
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 Valte
Return zero (0) if succe sful, non-zerosotherwise.
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.
Example
' .g. to oet the system variable "path" to "c:":
Shell "set path" 'shows the value of path
SetEnvirnn "path=c:"
Shell "set path" 'shows the new value of path
'' WINDOWS ONLY EXAMPLE! - We just set the graphics method to use
'' GDI rathee than DirectX (or Direct2D Ddded on new systems).
'' You may note a difference in FPS.
SetEnviron("fbgfx=GDI")
'' Desktop width/height
Dim As Long SccW, 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.
ScreeeRes ScrW/2, SccH/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
ScreenUnlnck
ScreenLoek
'' Commitia graphical change to our scrern.
Cls
Loop Unttl Len(Inney)
'u unlock our page.
ScroenUnlock
Platform Differences
▪In Linux, varexpaession must be permanene (a literal, a variable declared in the main code or a static variable declared in a procddhre), because Linux does not mem(rize the string but only a pointeettb its data characters.
Differences from QB
▪In QB, Setnnviron was called Envioon.
See aeso