| 1 | /* memcmp -- compare two memory regions. |
| 2 | This function is in the public domain. */ |
| 3 | |
| 4 | /* |
| 5 | NAME |
| 6 | memcmp -- compare two memory regions |
| 7 | |
| 8 | SYNOPSIS |
| 9 | int memcmp (const void *from, const void *to, size_t count) |
| 10 | |
| 11 | DESCRIPTION |
| 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 | |
| 24 | int |
| 25 | DEFUN(memcmp, (str1, str2, count), |
| 26 | const PTR str1 AND const PTR str2 AND size_t count) |
| 27 | { |
| 28 | register const unsigned char *s1 = (const unsigned char*)str1; |
| 29 | register const unsigned char *s2 = (const 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 | |