On 30/12/2020 13:56, Michael Kerrisk (man-pages) wrote: > Hello Jonny, > > On 12/24/20 6:52 PM, Jonny Grant wrote: >> Seasons greetings Michael, >> >> May I ask, could readlink be updated to use the same wording for null >> termination like on sprintf, scanf etc? >> >> https://man7.org/linux/man-pages/man2/readlink.2.html >> >> It says: >> "readlink() does not append a null byte to buf" >> >> Perhaps it should say: >> "readlink() does not append a terminating null byte to buf ('\0')" >> >> In addition, is it worth adding a BUGS section to remind that there >> is no terminating null byte? >> >> "readlink() assumes the caller understands that no terminating null >> byte ('\0') will be written in the provided buf. If the caller didn't >> memset the buffer to ('\0') or allocate an extra byte for the >> terminating null byte, there is a risk the caller could overrun the >> end of the buffer, or use uninitialised values in the buf." > >> >> Finally, perhaps also the EXAMPLES program could be updated to clarify this: >> >> "/* print only nbytes of buf, as it doesn't contain a terminating null byte ('\0') */ >> printf("'%s' points to '%.*s'\n", argv[1], (int) nbytes, buf); >> " > > I think that having (1) the existing statement at the start of the > DESCRIPTION, (2) adding a comment to the code, and (3) adding a BUGS > section all to cover the same point seems a little excessive. > I've gone for 2 out of 3. > > Thanks, > > Michael > > --- a/man2/readlink.2 > +++ b/man2/readlink.2 > @@ -93,7 +93,7 @@ in the buffer > which has size > .IR bufsiz . > .BR readlink () > -does not append a null byte to > +does not append a terminating null byte to > .IR buf . > It will (silently) truncate the contents (to a length of > .I bufsiz > @@ -332,6 +332,8 @@ main(int argc, char *argv[]) > exit(EXIT_FAILURE); > } > > + /* Print only \(aqnbytes\(aq of \(aqbuf\(aq, as it doesn't contain a terminating > + null byte (\(aq\e0\(aq). */ > printf("\(aq%s\(aq points to \(aq%.*s\(aq\en", argv[1], (int) nbytes, buf); > > /* If the return value was equal to the buffer size, then the > > Looks good, thank you. Jonny
