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Table Of Contents
AutoLISP provides two file formats for applications:
Reading an LSP file (.lsp)an ASCII text file that contains AutoLISP program
code.
Reading an FAS file (.fas)a binary, compiled version of a single LSP
program file.
NOTE
Like-named AutoLISP application files are loaded based on their Modified time
stamp; the LSP or FAS file with the most recent time stamp is loaded unless
you specify the full file name (including the file name extension).
Because AutoCAD can read AutoLISP code directly, no compiling is required.
This makes AutoLISP an easy language to experiment with, regardless of your
programming experience.
Even if you are not interested in writing AutoLISP applications, your AutoCAD
package includes many useful routines. Routines are also available as shareware
through third-party developers. Knowing how to load and use these routines
can enhance your productivity.
NOTE When command input comes from the AutoLISP command function, the
settings of the PICKADD and PICKAUTO system variables are assumed to be 1 and
0, respectively. This preserves compatibility with previous releases of AutoCAD
and makes customization easier (because you don't have to check the settings of
these variables).
For information about AutoLISP programming, see the AutoLISP Developer's
Guide, and for information about AutoLISP, see the AutoLISP Reference in the
Help system.
Use AutoLISP Applications
AutoLISP applications are stored in ASCII text files that you can edit. Before
you can use an AutoLISP application, it must first be loaded.
AutoLISP applications are stored in ASCII text files with the .lsp extension.
These files generally have a header portion that describes a routine, its use,
and any specific instructions. This header might also include comments that
document the author and the legal information regarding the use of the
routine. Comments are preceded by a semicolon (;). You can view and edit
these files with a text editor or word processor that can produce an ASCII text
file.
80 | Chapter 7 Introduction to Programming Interfaces