X-Git-Url: https://pd.if.org/git/?p=pdclib;a=blobdiff_plain;f=functions%2Fstring%2Fstrncmp.c;h=e1ec0de66e9797c9739555b4b901116ea4813920;hp=f64984ebc1b9ec4f5fc3a2e396560029124e6b89;hb=da0f3f353d417fed71f358a48d5d5394145e460d;hpb=c2f1367984ba4153d892062759c3813020b65a9a

diff --git a/functions/string/strncmp.c b/functions/string/strncmp.c
index f64984e..e1ec0de 100644
--- a/functions/string/strncmp.c
+++ b/functions/string/strncmp.c
@@ -1,7 +1,3 @@
-/* $Id$ */
-
-/* Release $Name$ */
-
 /* strncmp( const char *, const char *, size_t )
 
    This file is part of the Public Domain C Library (PDCLib).
@@ -10,20 +6,47 @@
 
 #include <string.h>
 
+#ifndef REGTEST
+
 int strncmp( const char * s1, const char * s2, size_t n )
 {
-    while ( n && ( *s1 == *s2 ) )
+    while ( *s1 && n && ( *s1 == *s2 ) )
     {
         ++s1;
         ++s2;
         --n;
     }
-    if ( ( n == 0 ) )
+    if ( n == 0 )
     {
         return 0;
     }
     else
     {
-        return ( *s1 - *s2 );
+        return ( *(unsigned char *)s1 - *(unsigned char *)s2 );
     }
 }
+
+#endif
+
+#ifdef TEST
+#include "_PDCLIB_test.h"
+
+int main( void )
+{
+    char cmpabcde[] = "abcde\0f";
+    char cmpabcd_[] = "abcde\xfc";
+    char empty[] = "";
+    char x[] = "x";
+    TESTCASE( strncmp( abcde, cmpabcde, 5 ) == 0 );
+    TESTCASE( strncmp( abcde, cmpabcde, 10 ) == 0 );
+    TESTCASE( strncmp( abcde, abcdx, 5 ) < 0 );
+    TESTCASE( strncmp( abcdx, abcde, 5 ) > 0 );
+    TESTCASE( strncmp( empty, abcde, 5 ) < 0 );
+    TESTCASE( strncmp( abcde, empty, 5 ) > 0 );
+    TESTCASE( strncmp( abcde, abcdx, 4 ) == 0 );
+    TESTCASE( strncmp( abcde, x, 0 ) == 0 );
+    TESTCASE( strncmp( abcde, x, 1 ) < 0 );
+    TESTCASE( strncmp( abcde, cmpabcd_, 10 ) < 0 );
+    return TEST_RESULTS;
+}
+#endif