2011

The following is a sample AutoLISP routine.
(defun C:SYMIN ( )
(setq sym
(getstring
"\nEnter symbol name: ") ; Prompts for a symbol name
)
(menucmd "s=symsize") ; Switches the screen menu
; to the symsize submenu
(setq
siz (getreal
"\nSelect symbol size: ") ; Prompts for a symbol size
p1 (getpoint
"\nInsertion point: ") ; Prompts for insertion point
)
(command "insert" ; Issues the INSERT command
sym ; using the desired symbol
p1 siz siz 0) ; insertion point, and size
(menucmd "s=") ; Switches to the previous
; screen menu
(princ) ; Exits quietly
)
NOTE An AutoLISP routine that you use regularly should include error checking
to verify the validity of user input.
The DIESEL expressions in the following example multiply the current value
of DIMSCALE by the specified value, and return an appropriate scale factor.
This cannot be done with similar AutoLISP code; a value returned by an
AutoLISP expression cannot typically be used as a response to a getxxx function
call (such as, the getreal function in the preceding sample).
$M=$(*,$(getvar,dimscale),0.375)
$M=$(*,$(getvar,dimscale),0.5)
$M=$(*,$(getvar,dimscale),0.625)
DIESEL expressions can also return string values to pull-down menu item
labels, so that you can make menus unavailable or otherwise alter the way
they are displayed. To use a DIESEL expression in a pull-down menu label,
make sure that the first character is the $ character.
In the next example, the current layer is set to BASE and the following DIESEL
expression is used as the label.
$(eval,"Current layer: " $(getvar,clayer))
DIESEL Expressions in Macros | 73