strdup(NULL) supposed to create SIGSEGV?
yanefbsd at gmail.com
Wed Apr 23 09:12:40 UTC 2008
On Wed, Apr 23, 2008 at 2:11 AM, Garrett Cooper <yanefbsd at gmail.com> wrote:
> On Tue, Apr 22, 2008 at 11:50 PM, Mike Meyer <mwm at mired.org> wrote:
> > On Tue, 22 Apr 2008 22:40:21 -0700
> > "Garrett Cooper" <yanefbsd at gmail.com> wrote:
> > > Hi all,
> > > I made an oops in a program, which uncovered "feature" in
> > strdup(2)
> > > that I wasn't aware of before. So I was wondering, is strdup(pointer =
> > NULL)
> > > supposed to segfault should this just return NULL and set errno?
> > Yes, it's supposed to segfault. Check out what, say, strcpy does if
> > you ask it to copy a NULL pointer. And this is an improvement from the
> > bad old days, when they would happily walk through memory starting at
> > 0.....
> > Besides, errno is used to signal errors from system calls. strdup
> > isn't a system call, it's a library function (says so at the top of
> > the man page).
> > > Good news is that Linux does the same thing (yay?), so at least
> > FreeBSD
> > > isn't alone..
> > Do you have examples of systems where strdup doesn't behave this way?
> > <mike
> No, I don't, but then again I just noticed this.
(and thanks for clarifying about errno; didn't realize that)
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