Re: strncmp issue

Hi, Channa--

On Apr 28, 2009, at 2:52 AM, Channa wrote:
I am using the freebsd implementation of strncmp for ARM which is an
assembly implementation.
I have a small doubt, when i tested the strncmp by passing the third argument:
'n' as -1 the return values is '0' instead it should '-1'.
When the third argument to strncmp is as below:

ret = strncmp("a","b",-1)

Thanks for the thought, but strncmp() is defined to take a size_t as the third argument, which is unsigned (ie, uint32_t or uint64_t).

Presumably when you tell it to compare with length of -1, that will be converted to UINT_MAX or ULONG_MAX, and strncmp() will run until it finds a null somewhere in one the strings and then return the comparison result. (Or get a segfault, perhaps, if you run off the end into unallocated address space.)

Regards,
--
-Chuck

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