X-Git-Url: https://pd.if.org/git/?p=pdclib;a=blobdiff_plain;f=functions%2Fstring%2Fmemcmp.c;h=323c5862db071c0378b954fe775de69ab3ad6aab;hp=43b7e585f348f3d112ef817009b94e38d97758ac;hb=da0f3f353d417fed71f358a48d5d5394145e460d;hpb=34893ecc2200dc7017c36a54cb6c5f4c2378b5ec

diff --git a/functions/string/memcmp.c b/functions/string/memcmp.c
index 43b7e58..323c586 100644
--- a/functions/string/memcmp.c
+++ b/functions/string/memcmp.c
@@ -1,8 +1,41 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// 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 */ };
+/* 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