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Load and Unload Menu Files
MNU Original ASCII menu file, the file you normally edit or create.
MNC Compiled menu file; a binary file that contains the command strings and menu syntax that define the functionality and appearance of the menu or other interface element. AutoCAD compiles this file when you load an MNU file for the first time.
MNR Menu resource file; a binary file that contains the bitmaps used by the menu or other interface element. AutoCAD generates this file each time it compiles an MNC file.
MNS Source menu file; an ASCII file that is the same as the MNU file but does not include comments or special formatting. AutoCAD modifies this file each time the contents of the menu file change.
MNT Menu resource file. This file is generated only when the MNR file is unavailable, for example, read-only.
MNL Menu LISP file; contains AutoLISP expressions that are used by the menu file. This file is loaded into memory when a menu file with the same file name is being loaded.
AutoCAD finds and loads the specified file according to the following sequence. This same sequence is used when AutoCAD loads a new menu.
1. AutoCAD looks for a menu source (MNS) file of the given name, following the library search procedure.
* If an MNS file is found, AutoCAD looks for a compiled menu (MNC) file of the same name in the same directory. If AutoCAD finds a matching MNC file with the same or later date and time as the MNS file, it loads the MNC file. Otherwise, AutoCAD compiles the MNS file, generating a new MNC file in the same directory, and loads that MNC file.
* If an MNS file is not found, AutoCAD looks for a compiled menu (MNC) file of the given name, following the library search procedure. If AutoCAD finds the MNC file, it loads that file.
* If neither an MNS nor an MNC file is found, AutoCAD searches the library path for a menu template (MNU) file of the given name. If this file is found, AutoCAD compiles an MNC file, generates an MNS file, and then loads the MNC file.
* If no files of the given name are found, AutoCAD displays an error message and prompts you for another menu file name.
2. After finding, compiling, and loading the MNC file, AutoCAD looks for a menu LISP (MNL) file, using the library search procedure. If AutoCAD finds this file, it evaluates the AutoLISP expressions within that file.