; GetEnv Example
; --------------

; GetEnv reads a variable out of this program's environment block.
; Windows sets these three for every process, so they always exist.

Print "USERNAME  = "+GetEnv$("USERNAME")
Print "OS        = "+GetEnv$("OS")
Print "CPU count = "+GetEnv$("NUMBER_OF_PROCESSORS")

Print ""

; A variable that is not set comes back as an empty string rather
; than an error, so Len() is the way to test for "not there"
missing$=GetEnv$("BLITZ3D_NO_SUCH_VARIABLE")
Print "Unset variable returned "+Len(missing)+" characters"

Print ""

; SetEnv writes one and GetEnv reads it straight back - handy for
; passing a level name or difficulty on to a program you ExecFile
SetEnv "BLITZ3D_DEMO_LEVEL","forest_ruins"
Print "After SetEnv: "+GetEnv$("BLITZ3D_DEMO_LEVEL")

; Tidy up - an empty value removes the variable again
SetEnv "BLITZ3D_DEMO_LEVEL",""
Print "After clearing: ["+GetEnv$("BLITZ3D_DEMO_LEVEL")+"]"

Print ""
Print "Press any key to close the example"
WaitKey

End