Hi Alejandro, > As hinted in recent mails to groff@ and linux-man@, > I'm going to inaugurate a new [sub]section for constants. This seems a bad idea. They're quite at home in section 3. > I think it should contain constants, normally represented by > object-like macros in C. But it should also contain other forms of > constants in other languages (e.g., C++'s constexpr variables), so I'm > not convinced by the name 3def. 3const was seem more in line with how you keep referring to it. > I'm (very) tempted to inaugurate section 11 for this That's seems a worse idea. They're far too trivial to deserve their own section. > The initial page for this section is non other than NULL ;) It seems a bit simple to be worthy of its own man page. > +.TH NULL 3def 2022-07-22 Linux "Linux Programmer's Manual" > +.SH NAME > +NULL \- null pointer constant It's one of them. An integer constant expression with the value 0 is also a null pointer constant. > +.SH SYNOPSIS > +.nf > +.B "#define NULL ((void *) 0)" Does the reader need to know the definition of a macro? Are you intending to do this for all macros and constants? > +A null pointer is one that doesn't point to a valid object. ...or function. > +When it is necessary to set a pointer variable to a null pointer, > +it is not enough to use > +.IR "memset(&p, 0, sizeof(p))" , > +since ISO C and POSIX don't guarantee that a bit pattern of all > +.BR 0 s > +would represent a null pointer. ‘p = 0’ would suffice there; it may be better to give the typical case where the pointer is part of a struct. Also, sizeof is an operator, not a function as the parenthesis and lack of space suggest. ‘memset(&p, 0, sizeof p)’ is clearer. Perhaps you're following some house style. > +.SH SEE ALSO > +.BR memset (3), > +.BR void (3type) More importantly, see also stddef.h(0p), as the man page hasn't yet told me how to obtain NULL's definition. Am I to copy the definition into my code? POSIX has a man page per standard header; that seems a good level to cover all the little things which each header file is defined to provide. If you really want to create work, consider a man page which tables NULL, EOF, etc., and the header-file man-page to read. -- Cheers, Ralph.
