X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstring%2Fmemchr.c;h=75809e079d62a7b35a789ca863cd113d059287a4;hb=4e46e25a507c6b6a7497adfc8ec9f9ab6e14addc;hp=83d6f1702c5fd3fc190d9082c4f577892ea604dc;hpb=34893ecc2200dc7017c36a54cb6c5f4c2378b5ec;p=pdclib

diff --git a/functions/string/memchr.c b/functions/string/memchr.c
index 83d6f17..75809e0 100644
--- a/functions/string/memchr.c
+++ b/functions/string/memchr.c
@@ -1,17 +1,40 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
+/* $Id$ */
 
-// ----------------------------------------------------------------------------
-// C++
+/* Release $Name$ */
 
-const void * memchr( const void * s, int c, size_t n ) { /* TODO */ };
-void * memchr( void * s, int c, size_t n ) { /* TODO */ };
+/* memchr( const void *, int, size_t )
 
-// ----------------------------------------------------------------------------
-// Standard C
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
 
-void * memchr( const void * s, int c, size_t n ) { /* TODO */ };
+#include <string.h>
+
+void * memchr( const void * s, int c, size_t n )
+{
+    const unsigned char * p = (const unsigned char *) s;
+    while ( n-- )
+    {
+        if ( *p == (unsigned char) c )
+        {
+            return (void *) p;
+        }
+        ++p;
+    }
+    return NULL;
+}
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main()
+{
+    BEGIN_TESTS;
+    TESTCASE( memchr( abcde, 'c', 5 ) == &abcde[2] );
+    TESTCASE( memchr( abcde, 'a', 1 ) == &abcde[0] );
+    TESTCASE( memchr( abcde, 'a', 0 ) == NULL );
+    TESTCASE( memchr( abcde, '\0', 5 ) == NULL );
+    TESTCASE( memchr( abcde, '\0', 6 ) == &abcde[5] );
+    return TEST_RESULTS;
+}
+#endif