TLEN stands for otal LEN gth. The TLEN.LSP file is a custom AutoLISP routine that does one thing very well: it calculates the sum of lengths for all objects you select in an AutoCAD drawing. The routine is lightweight, runs directly inside AutoCAD, and works on a variety of object types:
In the dialog box that appears, navigate to the folder where you saved tlen.lsp . Select the file and click .
Select the file, click , and ensure the status bar confirms "tlen.lsp successfully loaded". Click Close . Making it Permanent (Startup Suite)
Once the Lisp is loaded, using it is incredibly simple.
The script was only loaded into the active drawing session.
