Command Search Procedure
When you enter a command, AutoCAD LT goes through a series of steps to
evaluate the validity of the command name. A command can be a built-in
command or system variable or an alias defined in the acadlt.pgp file.
Commands can also be defined by a device driver command. You can enter
a command on the command prompt or choose a command from the
appropriate menu. Commands can also be entered from a script file.
The following list describes the search order AutoCAD LT uses to validate a
command name.
1 If the input is a null response (SPACEBAR or ENTER), AutoCAD LT uses
the name of the last command issued. HELP is the default.2 AutoCAD LT checks the command name against the list of built-in
commands. If the command is in the list and is not preceded by a period
(.), AutoCAD LT then checks the command against a list of undefined
commands. If the command is undefined, the search continues.
Otherwise, the command is run, unless another reason prevents it from
doing so. Running it transparently or in Perspective mode might be
impossible.3 AutoCAD LT checks the command name against the names of commands
defined by a device driver, and then by those defined by the display
driver.4 AutoCAD LT checks the command name against the list of system
variables. If the command name is in the list, AutoCAD LT executes the
SETVAR command, using the input as the variable name.5 If the command name corresponds to a command alias defined in the
program parameters file, AutoCAD LT uses the expanded command name
and continues the search, starting a new search against the list of built-in
commands.6 If all the preceding steps fail, the search terminates with a warning
message about illegal command names.See also:
■ “Specify Search Paths and File Locations” in the User's Guide
Overview of File Organization | 5