load (AutoLISP)

Evaluates the AutoLISP expressions in a file

Supported Platforms: Windows and Mac OS

Signature

(load filename [onfailure])

filename

Type: String

Name of the AutoLISP file to load. If the filename argument does not specify a file extension, load adds an extension to the name when searching for a file to load. The function will try several extensions, if necessary, in the following order:

• .vlx
• .fas
• .lsp

Note: VLX files are supported on Windows only.

As soon as load finds a match, it stops searching and loads the file.

The filename can include a directory prefix, as in c:/function/test1 (Windows) or /function/test1 (Mac OS). A forward slash (/) or two backslashes (\\) are valid directory delimiters. If you don't include a directory prefix in the filename string, load searches the AutoCAD library path for the specified file. If the file is found anywhere on this path, load then loads the file.

onfailure

Type: String

A value returned if load fails.

If the onfailure argument is a valid AutoLISP function, it is evaluated. In most cases, the onfailure argument should be a string or an atom. This allows an AutoLISP application calling load to take alternative action upon failure.

Remarks

The load function can be used from within another AutoLISP function, or even recursively (in the file being loaded).

Important: Starting with AutoCAD 2014-based products, custom applications must work under secure mode; when the SECURELOAD system variable is set to 1 or 2. When operating under secure mode, the program is restricted to loading and executing files that contain code from trusted locations; trusted locations are specified by the TRUSTEDPATHS system variable.

Return Values

Type: String, Subroutine, or Error

Unspecified, if successful. If load fails, it returns the value of onfailure; if onfailure is not defined, failure results in an error message.

Release Information

Releases:

• AutoCAD R12 and later on Windows
• AutoCAD 2011 and later on Mac OS

History

AutoCAD 2021

• filename argument previously accepted an ASCII text string, but now accepts a Unicode text string.
• LISPSYS system variable controls which AutoLISP engine is used and the behavior of the function.
  • 0 - ASCII character support (legacy behavior)
  • 1 or 2 - Unicode character support
  Note: After the value of the LISPSYS system variable has been changed, AutoCAD must be restarted for the change to take affect.

Examples

For the following examples, assume that file /fred/test1.lsp contains the expressions

(defun MY-FUNC1 (x) 
          ... function body ...
) 
(defun MY-FUNC2 (x) 
          ... function body ...
)

and that no file named test2 with a .lsp, .fas, or .vlx extension exists:

(load "/fred/test1")
MY-FUNC2

(load "\\fred\\test1")
MY-FUNC2

(load "/fred/test1" "bad")
MY-FUNC2

(load "test2" "bad")
"bad"

(load "test2")
; error: LOAD failed: "test2"