Unix text files
Bill Vaughn
bill at ur-cvsvax.UUCP
Thu Oct 31 07:55:29 AEST 1985
> > "Text consists of an ordered sequence of characters, with lines delimited
> > by newline characters. Text is normally terminated by a newline. This
> > newline should be considered to be followed by a (nonexistant) null line.
> > The null line should not be considered to be part of the text.
> > "If the last character of the text is not a newline, then consider
> > the text to be terminated by a newline - null line pair; however, this
> > newline - null line pair should not be considered to have been part of
> > the file.
> >
> > I *think* that's right...
> > Kay.
>
> Perhaps that is the best interpretation, but it sure is hard
> to put all that into a formal grammar, whereas the original
> concept was very simple:
>
> file ::= binary_file | text_file
> binary_file ::= { byte }*
> byte ::= <primitive unit of data, at least 8 bits>
> text_file ::= { text_line }*
> text_line ::= { text_char }* newline
> text_char ::= <7-bit ASCII character excluding NUL and newline>
> newline ::= <ASCII LF character>
Won't this change do it:
text_file ::= { text_line }* { text_char }*
I'm assuming that { something }* means zero or more occurences
of 'something'. I don't mean to imply that the change is desirable or
trivial, but it doesn't seem to be 'hard'.
Bill Vaughn
Univ. of Rochester
More information about the Comp.unix
mailing list