Hijack command - extract and alter output from vanilla commands

[darn halo]

Hi, this is a semi-universal question. Is there any way to make my lisproutin run a regullas AC-command and extract info from it. Likewise can i insert my own info in the output?

Example, i want my command to look like the output of massprop. But I also want it to write the unit afterwards so instead of it saying:

"Volume:                    3346204269.0" (Im based i mm)  it says "Volume:                    3.346204269 m³"

Basically im looking for a shortcut to not have to recreate the entire command byt just read info from it and modify the output. I could see this come in hand for a lot of customization.
 

[Lee Mac]

No - you cannot intercept and modify the output of standard commands, only redefine them.

[BIGAL]

Using massprop in a lisp is easy you just write it to a file then read what you want out of that file and display. Just always write to a known file. 

 

Just a question would the answer not be Litre's.

 

(defun c:vol ( / ent vol)
(setq ent (car (entsel "\nPick a solid ")))
(command "massprop" ent "" "Y" "D:\\acadtemp\\solid.mpr")
(setq fo (open "D:\\acadtemp\\solid.mpr" "R"))
(repeat 3
  (setq vol (read-line fo))
)
(setq vol (read-line fo))
(close fo)
(vl-file-delete "D:\\acadtemp\\solid.mpr")
(alert (strcat  vol))
(princ)
)