X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstring%2Fmemchr.c;h=fac50549cf0d0b9bf7041786737ca355f5cdde6a;hb=cd6cfe0f578c4f744ddc9a342243aff6b42f8027;hp=83d6f1702c5fd3fc190d9082c4f577892ea604dc;hpb=dcc8a8e99f69e090a03b7b868443addbc0817820;p=pdclib.old

diff --git a/functions/string/memchr.c b/functions/string/memchr.c
index 83d6f17..fac5054 100644
--- a/functions/string/memchr.c
+++ b/functions/string/memchr.c
@@ -1,17 +1,42 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
+/* $Id$ */
 
-// ----------------------------------------------------------------------------
-// C++
+/* memchr( const void *, int, size_t )
 
-const void * memchr( const void * s, int c, size_t n ) { /* TODO */ };
-void * memchr( void * s, int c, size_t n ) { /* TODO */ };
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
 
-// ----------------------------------------------------------------------------
-// Standard C
+#include <string.h>
 
-void * memchr( const void * s, int c, size_t n ) { /* TODO */ };
+#ifndef REGTEST
+
+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;
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    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