2012

Table Of Contents
8 Put the argument string in quotes.
Bit values 2 and 4 are mutually exclusive; if both are specified only the 2 bit
is used. Using value 2 or 4 without value 1 should be avoided, because
AutoCAD becomes unavailable until the application has completed.
Bit value 8 allows commands like del to work properly with file names that
have embedded spaces. This eliminates the possibility of passing a
space-delimited list of file names to these commands. If you prefer multiple
file support, do not use the bit value 8.
prompt An optional field. It specifies the prompt to display on the AutoCAD
command line or for the dynamic input tooltip. The response to this prompt
is appended to the string supplied in the executable field. If the first character
of the prompt field is an asterisk (*), the response can contain spaces and the
user must press Enter to terminate it. Otherwise, the response is terminated
by either Spacebar or Enter. If no prompt is specified, no input is requested;
however, you must add a comma if a return code is to be supplied or if you
want the prompt to have a trailing space.
return_code An optional bitcoded parameter. You can add these integer
values together in any combination to achieve the result you want. For
example, if values 1 and 2 are required, you use 3 as the return code. The values
are defined as follows (codes 0 and 4 are meaningless in a windowed
environment and are therefore not included):
1 Loads a DXB file. AutoCAD loads the DXB file named $cmd.dxb into the
drawing after the command is terminated. After the DXB file is loaded, the
$cmd.dxb file is deleted. This action produces the same result as the DXBIN
command.
2 Constructs a block definition from a DXB file. AutoCAD creates a block
definition from the DXB file named $cmd.dxb. The response to the prompt
field is used as the block name. This name must be a valid block name that
does not currently exist in the drawing; therefore, this mode cannot redefine
a previously defined block. After AutoCAD loads the DXB file, the $cmd.dxb
file is deleted. The default name for the INSERT command is set to the newly
defined block.
The file can also contain comment lines preceded by a semicolon (;).
Windows System Commands
The start and cmd Windows system commands are very useful when defining
external commands. If you specify an executable string that does not use the
start or cmd command, AutoCAD is unavailable until that window is closed.
22 | Chapter 1 Basic Customization