hey guys,
The presentation you're looking for was at the Arizona CFUG, which isn't
coming up right now... *but* with the wonders of Googles cache you can get
the article:
http://www.google.com/search?q=cache:www.azcfug.org/technotes/index.cfm%3Ffu
seaction%3Dadvancedcode%26technote%3Dbitmask+ColdFusion+bitmask&hl=en
HTH
Aaron Johnson, MCSE, MCP+I
Allaire Certified ColdFusion Developer
MINDSEYE, Inc.
<phn>617.350.0339
<fax>617.350.8884
<icq>66172567
[EMAIL PROTECTED]
> -----Original Message-----
> From: Cameron Childress [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, May 10, 2001 2:12 PM
> To: CF-Talk
> Subject: RE: Bit Masks
>
>
> > I believe that someone once gave a presentation at one of the
> CFUGs about
> > using bit masks, also know as Right Bit AND, to set up security access
> > levels. This wasn't the same as the presentation at the Fig Leaf site
> > that's slight more oriented towards hierarchy uses. I've looked
> > at all the
> > CFUG sites linked to from the Allaire site but I can't find the
> > presentation. Does anyone recall where the presentation was made
> > and/or how to get the presentation file?
>
> I once did a presentation a long time ago for the Atlanta CFUG on a simple
> security model that used bits in this fashion, but it was designed for
> CF4.0, and has a few outdated syntax samples in it if you are using
> something newer than 4.0. I'm emailing you a copy of it offlist.
> If anyone
> else wants it, please let me know offlist.
>
> Here's a bonus for working with bits... Slap the following code into a CFM
> template, run it, and them print the output. I keep a copy of it on my
> wall, and it really helps with remembering how the heck bit functions work
> and where the positions are/start etc...
>
> -Cameron
>
> --------------------
> Cameron Childress
> elliptIQ Inc.
> p.770.460.7277.232
> f.770.460.0963
>
> <!--- create the initial integers. Doing it this way helps you visualize
> what your int looks like in binary form --->
> <CFSET x = InputBaseN('00000000000000110000000000000001', 2)>
> <CFSET y = InputBaseN('00111111111111111111100111111110', 2)>
> <!--- position guide --->
> 10987654321098765432109876543210<BR>
>
> <CFOUTPUT>
> <!--- Read the bit values back out one by one to display the int in
> binary --->
> <CFLOOP INDEX="i" FROM="31" TO="0" STEP="-1">#BitMaskRead(x, i,
> 1)#</CFLOOP>
> = x = (#x#)<BR>
> <CFLOOP INDEX="i" FROM="31" TO="0" STEP="-1">#BitMaskRead(y, i,
> 1)#</CFLOOP>
> = y = (#y#)<BR>
> <BR>
> <!--- Do different bit operations BitAnd(), BitOr, etc, and see
> what they do
> to the values of the integers and bit positions. --->
> <CFLOOP INDEX="i" FROM="31" TO="0" STEP="-1">#BitMaskRead(BitAnd(x, y), i,
> 1)#</CFLOOP> = BitAnd(x, y) = #BitAnd(x, y)#<BR>
> <CFLOOP INDEX="i" FROM="31" TO="0" STEP="-1">#BitMaskRead(BitOr(x, y), i,
> 1)#</CFLOOP> = BitOr(x, y) = #BitOr(x, y)#<BR>
> <CFLOOP INDEX="i" FROM="31" TO="0" STEP="-1">#BitMaskRead(BitXOr(x, y), i,
> 1)#</CFLOOP> = BitXOr(x, y) = #BitXOr(x, y)#<BR>
> <CFLOOP INDEX="i" FROM="31" TO="0" STEP="-1">#BitMaskRead(BitNot(x), i,
> 1)#</CFLOOP> = BitNot(x) = #BitNot(x)#<BR>
> <CFLOOP INDEX="i" FROM="31" TO="0" STEP="-1">#BitMaskRead(BitNot(y), i,
> 1)#</CFLOOP> = BitNot(y) = #BitNot(y)#<BR>
>
>
>
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