Arguments

mask  (string, optional) pattern for the name part, can contain a folder; if omitted or NIL, "_VL~~" is used
folder  (string, optional) a folder for the temporary file name; if omitted or NIL, the folder from mask is used (if contained), or the folder as specified in TMP and TEMP environment variable(s)
extension  (string, optional) file name extension, if omitted or NIL, the extension from mask is used (if any, can be empty)

Return

(string) a unique name, suitable to create a (temporary) file

Example

(vl-filename-mktemp)
"J:\\Tempfile\\BricsCAD\\_VL~~000"

Remarks

note : only the first 5 characters from mask are taken to generate the file name !