Using Mline in a lisp routine

[jawf]

I need to see if anyone knows how to use Mline in a Lisp routine. I can do the following:

(command "mline" "st" "casing" pause pause pause "")

This allows the user to make an mline two segments long and no more, then continues the code for labeling, etc. Is there anyway to force the mline command to continue until the user decides he has enough segments and then continue the code?

Any help would be appreciated.

Thanks,
Joe Watkins

[scwegner]

Is there anyway to force the mline command to continue until the user decides he has enough segments and then continue the code?

There sure is.

    (command "mline" "st" "casing")
    (while 
      (= (logand (getvar "cmdactive") 1) 1)
      (command pause)
    );while

Or:

     (command "mline" "st" "casing")
     (while 
       (> (getvar "cmdactive") 0)
       (command pause)
     );while

[jawf]

Thanks. That works perfectly. I don't understand the LOGAND, though. I looked at the info I had on it and it didn't make sense to me. Any idea where I can get a better understanding of that type of function?

Thanks, Joe

[RobertB]

Logand works with bits (binary). It takes multiple arguments and returns a number that indicates the common bits in all the arguments. (Clear as mud, no?)

Example: 3=11 in binary, and 2=10 in binary. Are there any common bits? Yes, the bit in the 2nd "slot" (both are turned on, or set to 1). The least significant bit is not the same between the two (one is on, one is off).

11 AND 10 = 10
or
(logand 3 2) = 2
or
11 AND
10
10

More complex:
111
001
001
or
(logand 7 1) = 1

In the CmdActive system variable, unless you need to know if the command is active due to a script or other automation, simply testing for greater than 0 is enough, e.g. (> (getvar "CmdActive") 0)
Logand is useful there when you need to know if a script is running, i.e. is bit 2 (which equals 4) set.
(= (logand (getvar "CmdActive") 4) 4) or "Does the AND of CmdActive and 4 equal 4?"

[scwegner]

Logand compares a bit (as in binary 1 or 0) or bitset (as string of 1s and 0s) with a bitset to see if the bit is in the bitset. So, in this case, it looks at the number it receives from (getvar "cmdactive") and sees whether or not there is a 1 in it or if it's just a string of 0s. If it finds what it's looking for, it returns that (in this case a 1), otherwise it returns 0.

If that made no sense, this might be a better explanation:

http://discussion.autodesk.com/threa...sageID=2006356

[jawf]

OK. It has been a while since binary made sense. It does make some sense again. Thanks for all your patience.

Joe