Index: src/OFString.h
==================================================================
--- src/OFString.h
+++ src/OFString.h
@@ -124,10 +124,24 @@
  * \return An integer which is the result of the comparison, see for example
  *	   strcmp
  */
 - (int)compare: (id)obj;
 
+/**
+ * \param str The string to search
+ * \return The index of the first occurrence of the string or SIZE_MAX if it
+ *	   wasn't found
+ */
+- (size_t)indexOfFirstOccurrenceOfString: (OFString*)str;
+
+/**
+ * \param str The string to search
+ * \return The index of the last occurrence of the string or SIZE_MAX if it
+ *	   wasn't found
+ */
+- (size_t)indexOfLastOccurrenceOfString: (OFString*)str;
+
 /**
  * \param start The index where the substring starts
  * \param end The index where the substring ends.
  *	      This points BEHIND the last character!
  * \return The substring as a new autoreleased OFString

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -308,10 +308,51 @@
 		OF_HASH_ADD(hash, string[i]);
 	OF_HASH_FINALIZE(hash);
 
 	return hash;
 }
+
+- (size_t)indexOfFirstOccurrenceOfString: (OFString*)str
+{
+	const char *str_c = [str cString];
+	size_t str_len = [str length];
+	size_t i;
+
+	if (str_len == 0)
+		return 0;
+
+	if (str_len > length)
+		return SIZE_MAX;
+
+	for (i = 0; i <= length - str_len; i++)
+		if (!memcmp(string + i, str_c, str_len))
+			return i;
+
+	return SIZE_MAX;
+}
+
+- (size_t)indexOfLastOccurrenceOfString: (OFString*)str
+{
+	const char *str_c = [str cString];
+	size_t str_len = [str length];
+	size_t i;
+
+	if (str_len == 0)
+		return length;
+
+	if (str_len > length)
+		return SIZE_MAX;
+
+	for (i = length - str_len;; i--) {
+		if (!memcmp(string + i, str_c, str_len))
+			return i;
+
+		/* Did not match and we're at the last char */
+		if (i == 0)
+			return SIZE_MAX;
+	}
+}
 
 - (OFString*)substringFromIndex: (size_t)start
 			toIndex: (size_t)end
 {
 	char *tmp;

Index: tests/OFString/OFString.m
==================================================================
--- tests/OFString/OFString.m
+++ tests/OFString/OFString.m
@@ -23,11 +23,11 @@
 #define ZD "%zd"
 #else
 #define ZD "%u"
 #endif
 
-#define NUM_TESTS 39
+#define NUM_TESTS 47
 #define SUCCESS								\
 	printf("\r\033[1;%dmTests successful: " ZD "/%d\033[0m",	\
 	    (i == NUM_TESTS - 1 ? 32 : 33), i + 1, NUM_TESTS);		\
 	fflush(stdout);
 #define FAIL								\
@@ -99,10 +99,20 @@
 	CHECK(!strcmp([s1 cString], "test: 123"))
 
 	[s1 appendWithFormat: @"%02X", 15];
 	CHECK(!strcmp([s1 cString], "test: 1230F"))
 
+	/* Find index tests */
+	CHECK([@"foo" indexOfFirstOccurrenceOfString: @"oo"] == 1)
+	CHECK([@"foo" indexOfLastOccurrenceOfString: @"oo"] == 1)
+	CHECK([@"foo" indexOfFirstOccurrenceOfString: @"o"] == 1)
+	CHECK([@"foo" indexOfLastOccurrenceOfString: @"o"] == 2)
+	CHECK([@"foo" indexOfFirstOccurrenceOfString: @"f"] == 0)
+	CHECK([@"foo" indexOfLastOccurrenceOfString: @"f"] == 0)
+	CHECK([@"foo" indexOfFirstOccurrenceOfString: @"x"] == SIZE_MAX)
+	CHECK([@"foo" indexOfLastOccurrenceOfString: @"x"] == SIZE_MAX)
+
 	/* Substring tests */
 	CHECK([[@"foo" substringFromIndex: 1
 				  toIndex: 2] isEqual: @"o"]);
 	CHECK([[@"foo" substringFromIndex: 3
 				  toIndex: 3] isEqual: @""]);