X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstring%2Fmemcmp.c;h=3ac32a213c89d21800d60b80b1926ba0efa90dc0;hb=cc20fa1b34370b71d828d2985a10f69be1f0e65c;hp=8a4a070e0127d25d94ef41f3d58e607487a2639e;hpb=c0169638bd02098717cb23fbbca3bcc4e4caccf0;p=pdclib

diff --git a/functions/string/memcmp.c b/functions/string/memcmp.c
index 8a4a070..3ac32a2 100644
--- a/functions/string/memcmp.c
+++ b/functions/string/memcmp.c
@@ -18,7 +18,7 @@ int memcmp( const void * s1, const void * s2, size_t n )
     {
         if ( *p1 != *p2 )
         {
-            return *p2 - *p1;
+            return *p1 - *p2;
         }
         ++p1;
         ++p2;
@@ -26,4 +26,17 @@ int memcmp( const void * s1, const void * s2, size_t n )
     return 0;
 }
 
-#warning Test driver missing.
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main()
+{
+    char const xxxxx[] = "xxxxx";
+    BEGIN_TESTS;
+    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