Date: Tue, 10 Feb 2004 15:34:39 -0500 From: Bill Moran <wmoran@potentialtech.com> To: Ben Smithurst <ben@FreeBSD.org> Cc: freebsd-chat@freebsd.org Subject: Re: Could use some help with variable length argument lists Message-ID: <4029405F.1090609@potentialtech.com> In-Reply-To: <20040210202025.GA93986@strontium.bcxs.net> References: <40293B38.30401@potentialtech.com> <20040210202025.GA93986@strontium.bcxs.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Ben Smithurst wrote:
> Bill Moran wrote:
>
>> char **format, **errmsg;
>>
>> va_start(ap, message);
>> if (level <= LOGLEVEL) {
>> asprintf(format, "PID %d: %s", getpid(), message);
> ...
>
>>Doesn't seem too difficult, right? However, if I call the function
>>from elsewhere in my application like this:
>>
>>_log(1, "Log test");
>>
>>I get a coredump! gdb complains that message is "out of bounds"
>>on the line "asprintf(format, "PID %d: %s", getpid(), message);"
>
> are you sure it isn't the format variable causing the problem? It's
> a while since I've used asprintf() but from memory you should write
> something more like
>
> char *format;
> ...
> asprintf(&format, "PID %d: %s", getpid(), message);
>
> Your code above is passing format uninitialized (you should have got a
> compile time warning about that).
>
> Or maybe I'm misunderstanding something. :-)
Nope. You're understanding far more clearly than I, today.
Your suggestion fixed it! I owe you a big one, if you're ever in
western PA, give me a call, the drinks are on me - you've earned it!
I guess it just goes to show that I've been sitting in front of this
computer too long ;)
--
Bill Moran
Potential Technologies
http://www.potentialtech.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4029405F.1090609>