[Tony Trinh <tony19@xxxxxxxxx>]

On Mon, Sep 3, 2012 at 5:50 PM, Jaap Keuter <jaap.keuter@xxxxxxxxx> wrote:

Anyone knows what strstr() does with a NULL for a haystack? As far as I can tell it's unspecified.

I think you're right. "Undefined/unspecified behavior" usually means a segfault from my experience. This is true for strstr() in OSX ML.

strstr() apparently does not null-check its parameters in the latest versions of Linux [1], OSX/Darwin (and probably other Un*x) [2], and Windows [3]. I couldn't find the Windows source for strstr(), but MSDN indicates:

strstr and wcsstr do not validate their parameters.

Interestingly, Windows does have an error handler in _mbsstr() for invalid parameters.

[1]: http://lxr.linux.no/linux+v3.5.3/lib/string.c

[2]: http://www.opensource.apple.com/source/xnu/xnu-792.13.8/libsa/strstr.c

[3]: http://msdn.microsoft.com/en-us/library/z9da80kz.aspx