From 5d826ec284603553311b71eab304484a3589c6bc Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Sun, 4 Mar 2012 17:20:42 +0100
Subject: [PATCH] Added strstr(3).

---
 libmaxsi/include/string.h |  2 +-
 libmaxsi/string.cpp       | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/libmaxsi/include/string.h b/libmaxsi/include/string.h
index a7ed294e..80a2be64 100644
--- a/libmaxsi/include/string.h
+++ b/libmaxsi/include/string.h
@@ -52,6 +52,7 @@ int strncmp(const char*, const char*, size_t);
 char* strncpy(char* restrict, const char* restrict, size_t);
 char* strrchr(const char*, int);
 size_t strspn(const char*, const char*);
+char* strstr(const char*, const char*);
 char* strtok(char* restrict, const char* restrict);
 char* strtok_r(char* restrict, const char* restrict, char** restrict);
 
@@ -67,7 +68,6 @@ char* strndup(const char*, size_t);
 size_t strnlen(const char*, size_t);
 char* strpbrk(const char*, const char*);
 char* strsignal(int);
-char* strstr(const char*, const char*);
 size_t strxfrm(char* restrict, const char* restrict, size_t);
 size_t strxfrm_l(char* restrict, const char* restrict, size_t, locale_t);
 #endif
diff --git a/libmaxsi/string.cpp b/libmaxsi/string.cpp
index b7bb7ff7..e539901d 100644
--- a/libmaxsi/string.cpp
+++ b/libmaxsi/string.cpp
@@ -244,6 +244,24 @@ namespace Maxsi
 			return result;
 		}
 
+		// TODO: This simple and hacky implementation runs in O(N^2) even though
+		// this problem can be solved in O(N).
+		char* strstr(const char* haystack, const char* needle)
+		{
+			if ( !needle[0] ) { return (char*) haystack; }
+			for ( size_t i = 0; haystack[i]; i++ )
+			{
+				bool diff = false;
+				for ( size_t j = 0; needle[j]; j++ )
+				{
+					if ( haystack[i+j] != needle[j] ) { diff = true; break; }
+				}
+				if ( diff ) { continue; }
+				return (char*) haystack + i;
+			}
+			return NULL;
+		}
+
 #ifndef SORTIX_KERNEL
 		extern "C" char* strdup(const char* input)
 		{