web2c: \input quoted filename

 
 4.5.1 '\input' quoted filename: '\input "some name"'
 ----------------------------------------------------
 
 As of Web2c version 7.5.3 (2004), double-quote characters can be used to
 include spaces or other special characters.  In typical use, the '"'
 characters surround the entire filename:
      \input "filename with spaces"
 
    Technically, the quote characters can be used inside the name, and
 can enclose any characters, as in:
      \input filename" "with" "spaces
 
    One more point.  In LaTeX, the quotes are needed inside the braces of
 its '\input' macro, thus:
      \input{a b}    % fails
      \input{"a b"}  % ok
 
    There is no way to quote the quote character.