/* memcmp -- compare two memory regions. This function is in the public domain. */ /* @deftypefn Supplemental int memcmp (const void *@var{x}, const void *@var{y}, @ size_t @var{count}) Compares the first @var{count} bytes of two areas of memory. Returns zero if they are the same, a value less than zero if @var{x} is lexically less than @var{y}, or a value greater than zero if @var{x} is lexically greater than @var{y}. Note that lexical order is determined as if comparing unsigned char arrays. @end deftypefn */ #include <ansidecl.h> #include <stddef.h> int memcmp (const PTR str1, const PTR str2, size_t count) { register const unsigned char *s1 = (const unsigned char*)str1; register const unsigned char *s2 = (const unsigned char*)str2; while (count-- > 0) { if (*s1++ != *s2++) return s1[-1] < s2[-1] ? -1 : 1; } return 0; }