X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstring%2Fmemmove.c;h=af8981358414436351221d091cbb50bd52943232;hb=d865c4403fc91d1f1ac95ba76febcee9f429bb97;hp=9ecce5db20fa32741d4ab4164fa6214a38d3dde9;hpb=34893ecc2200dc7017c36a54cb6c5f4c2378b5ec;p=pdclib

diff --git a/functions/string/memmove.c b/functions/string/memmove.c
index 9ecce5d..af89813 100644
--- a/functions/string/memmove.c
+++ b/functions/string/memmove.c
@@ -1,8 +1,52 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
-
-void * memmove( void * s1, const void * s2, size_t n ) { /* TODO */ };
+/* memmove( 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
+
+void * memmove( void * s1, const void * s2, size_t n )
+{
+    char * dest = (char *) s1;
+    const char * src = (const char *) s2;
+    if ( dest <= src )
+    {
+        while ( n-- )
+        {
+            *dest++ = *src++;
+        }
+    }
+    else
+    {
+        src += n;
+        dest += n;
+        while ( n-- )
+        {
+            *--dest = *--src;
+        }
+    }
+    return s1;
+}
+
+#endif
+
+#ifdef TEST
+
+#include "_PDCLIB_test.h"
+
+int main( void )
+{
+    char s[] = "xxxxabcde";
+    TESTCASE( memmove( s, s + 4, 5 ) == s );
+    TESTCASE( s[0] == 'a' );
+    TESTCASE( s[4] == 'e' );
+    TESTCASE( s[5] == 'b' );
+    TESTCASE( memmove( s + 4, s, 5 ) == s + 4 );
+    TESTCASE( s[4] == 'a' );
+    return TEST_RESULTS;
+}
+
+#endif