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 -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
