Re: [?OT?] strndup exists in FreeBSD?
On Tue, 15 Apr 2008 01:26:40 +0200, Mel <[EMAIL PROTECTED]> wrote: > On Tuesday 15 April 2008 01:06:24 Giorgos Keramidas wrote: >> On Mon, 14 Apr 2008 15:43:24 -0700, "Steve Franks" <[EMAIL PROTECTED]> > wrote: >> > I'm getting an undefined reference to strndup, so clearly there's a >> > header somewhere with it - doesn't seem to be in my default libc, >> > however on 7.0-amd64? >> >> I don't see an strndup() function in our libc. >> >> [EMAIL PROTECTED]:/usr/src/lib/libc/string$ grep ^strdup *.c >> strdup.c:strdup(str) >> [EMAIL PROTECTED]:/usr/src/lib/libc/string$ grep ^strndup *.c >> [EMAIL PROTECTED]:/usr/src/lib/libc/string$ >> >> While it seems like a cool function name, what's the point of having it? >> If you know how much you want to copy, it's trivial to allocate a buffer >> large enough and strlcpy() into it. If you don't know how much you want >> to copy, then strdup() is ok anyway :) > > It can be convenient for trickery: > char file[MAXPATHLEN]; > char *dir; > ... > dir = strndup(file, (strrchr(file, '/')-file))); I know, but I don't feel safe when I see code like this. All sorts of amusing things can happen when it's used this way and strrchr() returns NULL though, so it is safer to explicitly allocate buffers and check what's going on. > Or space optimization: > char *p, *path; > path = malloc(MAXPATHLEN); > (void)strlcpy(path, argv[i], MAXPATHLEN); > p = strndup(path, strlen(path)); > free(path); > > But, personally I prefer taking the long route or wasting a few bytes > over dual allocations. I can definitely agree with this part :) ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: [?OT?] strndup exists in FreeBSD?
On Mon, 14 Apr 2008 16:27:42 -0700, "Steve Franks" <[EMAIL PROTECTED]> wrote: >> While it seems like a cool function name, what's the point of having it? >> If you know how much you want to copy, it's trivial to allocate a buffer >> large enough and strlcpy() into it. If you don't know how much you want >> to copy, then strdup() is ok anyway :) > > Granted. It's just one more thing to hack when porting linux code > (which I'm getting rather tired of doing, I must admit - they seem to > assume everyone likes to include every new api ever concieved, then > they go off and use them...) Ah, I see now. I think I know the feeling... I just saw a diff fly by at the review emails at work, which replaced strlcpy() with strncpy() because of a similar problem, only this time the other way around. The libc of BSD and Solaris includes strlcpy() and strlcat(), but it's unavailable in Linux, so we have to either "hack around" the missing feature with strncpy() or conditionally include a BSD licensed version of strlcpy() to our compatibility cruft. ``Portability is a huge chimera.'' Oh well :( ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: [?OT?] strndup exists in FreeBSD?
> While it seems like a cool function name, what's the point of having it? > If you know how much you want to copy, it's trivial to allocate a buffer > large enough and strlcpy() into it. If you don't know how much you want > to copy, then strdup() is ok anyway :) Granted. It's just one more thing to hack when porting linux code (which I'm getting rather tired of doing, I must admit - they seem to assume everyone likes to include every new api ever concieved, then they go off and use them...) Steve ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: [?OT?] strndup exists in FreeBSD?
On Tuesday 15 April 2008 01:06:24 Giorgos Keramidas wrote: > On Mon, 14 Apr 2008 15:43:24 -0700, "Steve Franks" <[EMAIL PROTECTED]> wrote: > > I'm getting an undefined reference to strndup, so clearly there's a > > header somewhere with it - doesn't seem to be in my default libc, > > however on 7.0-amd64? > > I don't see an strndup() function in our libc. > > [EMAIL PROTECTED]:/usr/src/lib/libc/string$ grep ^strdup *.c > strdup.c:strdup(str) > [EMAIL PROTECTED]:/usr/src/lib/libc/string$ grep ^strndup *.c > [EMAIL PROTECTED]:/usr/src/lib/libc/string$ > > While it seems like a cool function name, what's the point of having it? > If you know how much you want to copy, it's trivial to allocate a buffer > large enough and strlcpy() into it. If you don't know how much you want > to copy, then strdup() is ok anyway :) It can be convenient for trickery: char file[MAXPATHLEN]; char *dir; ... dir = strndup(file, (strrchr(file, '/')-file))); Or space optimization: char *p, *path; path = malloc(MAXPATHLEN); (void)strlcpy(path, argv[i], MAXPATHLEN); p = strndup(path, strlen(path)); free(path); But, personally I prefer taking the long route or wasting a few bytes over dual allocations. -- Mel Problem with today's modular software: they start with the modules and never get to the software part. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: [?OT?] strndup exists in FreeBSD?
On Mon, 14 Apr 2008 15:43:24 -0700, "Steve Franks" <[EMAIL PROTECTED]> wrote: > I'm getting an undefined reference to strndup, so clearly there's a > header somewhere with it - doesn't seem to be in my default libc, > however on 7.0-amd64? I don't see an strndup() function in our libc. [EMAIL PROTECTED]:/usr/src/lib/libc/string$ grep ^strdup *.c strdup.c:strdup(str) [EMAIL PROTECTED]:/usr/src/lib/libc/string$ grep ^strndup *.c [EMAIL PROTECTED]:/usr/src/lib/libc/string$ While it seems like a cool function name, what's the point of having it? If you know how much you want to copy, it's trivial to allocate a buffer large enough and strlcpy() into it. If you don't know how much you want to copy, then strdup() is ok anyway :) ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: [?OT?] strndup exists in FreeBSD?
On Tuesday 15 April 2008 00:43:24 Steve Franks wrote: > I'm getting an undefined reference to strndup, so clearly there's a > header somewhere with it - doesn't seem to be in my default libc, > however on 7.0-amd64? as BUF_strndup. And no, there's no strndup. -- Mel Problem with today's modular software: they start with the modules and never get to the software part. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
[?OT?] strndup exists in FreeBSD?
I'm getting an undefined reference to strndup, so clearly there's a header somewhere with it - doesn't seem to be in my default libc, however on 7.0-amd64? Thanks, Steve ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
