When the ‘-e’ option is in effect, FWEB attempts to be helpful in figuring out what file name one intends. For any input file name that has no extension (no embedded period), FWEB completes the name by adding the extension contained in the style-file parameter listed in the following table:
Type of file Style-file entry Default WEB fileext.web
web
Change fileext.ch
ch
Include fileext.hweb
hweb
Change file for include fileext.hch
hch
More than one extension may be specified, as a space-delimited list—e.g., ‘ext.web = "web wb"’; the first one that matches is used.