Reviewed.

[pdclib] / functions / string / strstr.c

diff --git a/functions/string/strstr.c b/functions/string/strstr.c
index b2494234b23df4944ef119071c7e04ed40e3be8f..55f1db60dab91bf4a886fdc37ab099ec10ac0de9 100644 (file)
--- a/functions/string/strstr.c
+++ b/functions/string/strstr.c
@@ -5,13 +5,26 @@
 // This code is Public Domain. Use, modify, and redistribute at will.
 // ----------------------------------------------------------------------------
 
-// ----------------------------------------------------------------------------
-// C++
-
-const char * strstr( const char * s1, const char * s2 ) { /* TODO */ };
-char * strstr( char * s1, const char * s2 ) { /* TODO */ };
-
-// ----------------------------------------------------------------------------
-// Standard C
+#include <__NULL.h>
 
-char * strstr( const char * s1, const char * s2 ) { /* TODO */ };
+char * strstr( const char * src_1, const char * src_2 )
+{
+    const char * p1 = src_1;
+    const char * p2;
+    while ( *src_1 != '\0' )
+    {
+        p2 = src_2;
+        while ( ( *p2 != '\0' ) && ( *p1 == *p2 ) )
+        {
+            ++p1;
+            ++p2;
+        }
+        if ( *p2 == '\0' )
+        {
+            return (char *) src_1;
+        }
+        ++src_1;
+        p1 = src_1;
+    }
+    return NULL;
+}