cswiger at mac.com
Tue Apr 28 17:26:04 UTC 2009
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
> '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.)
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