See all environment VARS

Blitz3D Forums/Blitz3D Programming/See all environment VARS

virtlands

(Posted 2013) [#1]

; Hi, this Blitz3D program demonstrates a quick and easy
; method to display ALL environment variable strings,
;
; --

THIS CODE HAS BEEN UPDATED, SCROLL DOWN BELOW to see Version 2
;
;

Yue	(Posted 2013) [#2]

nice!! :)

virtlands

(Posted 2013) [#3]

; Glad you like it Yue.

;

; I had some free time, and came up with an idea that may be a small improvement for this program.

; Click here to download the updated code,
http://uploadingit.com/file/ss7vvemoyfihuvki/envvars_V2.zip

; (The link includes updated PureBasic code, B3D code, as well as the DLL.)

; Blitz3D function version 1 is SeeEnvVar()
; Blitz3D function version 2 is SeeEnvVarT()

; As you know, any function can only return one string at a time, and
; therefore in function version 1 of the environment variables thing
; I had to combine two strings together in the form "NAME=VALUE" in order to return a value.

; The "Name=Value" format may be kind of annoying for usage because
; then the user has to dissect it apart again back into its components, ...

; Therefore I came up with the idea in Version 2 of letting the function
; "pulse" out data, (it spits out data one part at a time per each function time).
;
; I know this is a weird idea, but it works.

The Function usage is really simple, like this:

{ e1 and e2 are special string constants that allow detection of "end of list", or "error". }

The first call to the function returns an env "Name",
then calling the function again returns the env "Value".

The DLL code keeps track of the function's internal state with special Global vars.

[shown here is a portion of the PureBasic DLL code]

; ----------------------------------------------------------

Obviously, there is the potential to return a structure TYPE that
contains 2 strings in it, ... but it's kind of complicated to do that
with a DLL, don't you think?

{ This B3D code is already included in the above download link. }

 ;; Quick & Easy Environment string reader _VERSION 2
 ;; shall loop through every single ENVIRONMENT VARIABLE that it finds
 ;;
 ;; created by VirtLands { Feb 07,2013 }
 ;; This program requires an accompanying DLL, = "envvars.DLL"

 ; ---  For your USERLIBS directory,  . . .
 ; ---- create a file called  "ENVVARS.decls", 
 ; ---- and copy the following 2 text lines to it.
 ;  .lib "ENVVARS.dll"
 ;  SeeEnvVar$()
 ;  SeeEnvVarT$()   ;; <--- new, improved version of the Function 
 
 ; ----------------------------------------------------------------------------------------------
 ; These 2 constants are built into the DLL, therefore we need to detect them.
 ;
 Const  e1$ = "env_read_error"     ;; some malfunction happened, so can't continue.
 Const  e2$ = "env_end_of_list"    ;; the end of the Enviroment list has happened.

 Graphics 800,700,32,2

 Local envCount=0
 Local s1$,s2$
  
 Global MAX=50
 Dim envName$(max), envValue$(max)
 
 For z=1 To MAX 
       s1 = SeeEnvVarT()   ;; get environment variable NAME
       s2 = SeeEnvVarT()   ;; get environment variable VALUE

       If (s1=e1) Or (s1=e2)
               Exit
       Else 
               envName(z)=s1 : envValue(z)=s2   
               envcount = envcount +1
       End If    
 Next 

       ;; Now display all the environment variables
 For z=1 To envcount     
       Print"  "+envName(z)+" = "+envValue(z)
 Next 

 Print:Print" --- "+envcount+" environment vars have been listed. --- "
 WaitKey():End

;; I was thinking that "pulsed" functions can have lots of possibilities,
;; and beyond the "environment vars" sample.