memcmp.c revision 33965 
1/* memcmp -- compare two memory regions.
2   This function is in the public domain.  */
3
4/*
5NAME
6	memcmp -- compare two memory regions
7
8SYNOPSIS
9	int memcmp (const void *from, const void *to, size_t count)
10
11DESCRIPTION
12	Compare two memory regions and return less than,
13	equal to, or greater than zero, according to lexicographical
14	ordering of the compared regions.
15*/
16
17#include <ansidecl.h>
18#ifdef __STDC__
19#include <stddef.h>
20#else
21#define size_t unsigned long
22#endif
23
24int
25DEFUN(memcmp, (str1, str2, count),
26      const PTR str1 AND const PTR str2 AND size_t count)
27{
28  register unsigned char *s1 = (unsigned char*)str1;
29  register unsigned char *s2 = (unsigned char*)str2;
30
31  while (count-- > 0)
32    {
33      if (*s1++ != *s2++)
34	  return s1[-1] < s2[-1] ? -1 : 1;
35    }
36  return 0;
37}
38
39