Invokes the Help facility
Supported Platforms: Windows, Mac OS, and Web
Signature
(help [helpfile [topic [command]]])
- helpfile
-
Type: String
Help file name.
Note: If an empty string is provided, AutoCAD will try to open the topic in the Online help associated with and available for the product.The file extension is not required with the helpfile argument. If a file extension is provided, AutoCAD looks only for a file with the exact name specified.
If no file extension is provided, AutoCAD looks for helpfile with an extension of .chm. If no file of that name is found, AutoCAD looks for a file with an extension of .hlp.
Note: It is recommended to place help files in a folder that doesn't contain Unicode characters. The Microsoft® HTML Help Executable doesn't support paths with Unicode characters, so the help files might not open as expected. - topic
-
Type: String
Help topic ID.
If you are calling a topic within a CHM file, provide the file name without the extension; AutoCAD adds an .htm extension.
- command (Windows only)
-
Type: String
Specifies the initial state of the Help window. The command argument is a string used by the uCommand (in HTML Help) or the fuCommand (in WinHelp) argument of the HtmlHelp() and WinHelp() functions as defined in the Microsoft Windows SDK.
For HTML Help files, the command parameter can be HH_ALINK_LOOKUP or HH_DISPLAY_TOPIC. For Windows Help files, the command parameter can be HELP_CONTENTS, HELP_HELPONHELP, or HELP_PARTIALKEY.
Return Values
Type: String or nil
The helpfile string, if successful; otherwise nil. If you use help without any arguments, it returns an empty string ("") if successful, and nil if it fails.
The only error condition that the help function returns to the application is the existence of the file specified by helpfile. All other error conditions are reported to the user through a dialog box.
Remarks
Examples
The following code calls help to display the information on MYCOMMAND in the Help file achelp.chm:
(help "achelp.chm" "mycommand")