-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
-
-int memcmp( const void * s1, const void * s2, size_t n ) { /* TODO */ };
+/* $Id$ */
+
+/* memcmp( const void *, const void *, size_t )
+
+ This file is part of the Public Domain C Library (PDCLib).
+ Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <string.h>
+
+#ifndef REGTEST
+
+int memcmp( const void * s1, const void * s2, size_t n )
+{
+ const unsigned char * p1 = (const unsigned char *) s1;
+ const unsigned char * p2 = (const unsigned char *) s2;
+ while ( n-- )
+ {
+ if ( *p1 != *p2 )
+ {
+ return *p1 - *p2;
+ }
+ ++p1;
+ ++p2;
+ }
+ return 0;
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+ char const xxxxx[] = "xxxxx";
+ TESTCASE( memcmp( abcde, abcdx, 5 ) < 0 );
+ TESTCASE( memcmp( abcde, abcdx, 4 ) == 0 );
+ TESTCASE( memcmp( abcde, xxxxx, 0 ) == 0 );
+ TESTCASE( memcmp( xxxxx, abcde, 1 ) > 0 );
+ return 0;
+}
+#endif