Index: src/OFString.h
==================================================================
--- src/OFString.h
+++ src/OFString.h
@@ -124,10 +124,19 @@
  * \return An integer which is the result of the comparison, see for example
  *	   strcmp
  */
 - (int)compare: (id)obj;
 
+/**
+ * \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
+ */
+- (OFString*)substringFromIndex: (size_t)start
+			toIndex: (size_t)end;
+
 /**
  * Splits an OFString into an OFArray of OFStrings.
  *
  * \param delimiter The delimiter for splitting
  * \return An autoreleased OFArray with the splitted string

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -308,10 +308,43 @@
 		OF_HASH_ADD(hash, string[i]);
 	OF_HASH_FINALIZE(hash);
 
 	return hash;
 }
+
+- (OFString*)substringFromIndex: (size_t)start
+			toIndex: (size_t)end
+{
+	char *tmp;
+	size_t len;
+	OFString *ret;
+
+	if (start > end)
+		@throw [OFInvalidArgumentException newWithClass: isa
+						    andSelector: _cmd];
+
+	if (end > length)
+		@throw [OFOutOfRangeException newWithClass: isa];
+
+	len = end - start;
+
+	if ((tmp = malloc(len + 1)) == NULL)
+		@throw [OFOutOfMemoryException newWithClass: isa
+						    andSize: len + 1];
+
+	if (len)
+		memcpy(tmp, string + start, len);
+	tmp[len] = 0;
+
+	@try {
+		ret = [OFString stringWithCString: tmp];
+	} @finally {
+		free(tmp);
+	}
+
+	return ret;
+}
 
 - (OFArray*)splitWithDelimiter: (OFString*)delimiter
 {
 	OFAutoreleasePool *pool;
 	OFArray *array = nil;

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 34
+#define NUM_TESTS 39
 #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 +99,22 @@
 	CHECK(!strcmp([s1 cString], "test: 123"))
 
 	[s1 appendWithFormat: @"%02X", 15];
 	CHECK(!strcmp([s1 cString], "test: 1230F"))
 
+	/* Substring tests */
+	CHECK([[@"foo" substringFromIndex: 1
+				  toIndex: 2] isEqual: @"o"]);
+	CHECK([[@"foo" substringFromIndex: 3
+				  toIndex: 3] isEqual: @""]);
+	CHECK_EXCEPT([@"foo" substringFromIndex: 2
+					toIndex: 4], OFOutOfRangeException)
+	CHECK_EXCEPT([@"foo" substringFromIndex: 4
+					toIndex: 4], OFOutOfRangeException)
+	CHECK_EXCEPT([@"foo" substringFromIndex: 2
+					toIndex: 0], OFInvalidArgumentException)
+
 	/* Split tests */
 	a = [@"fooXXbarXXXXbazXXXX" splitWithDelimiter: @"XX"];
 	CHECK([[a objectAtIndex: j++] isEqual: @"foo"])
 	CHECK([[a objectAtIndex: j++] isEqual: @"bar"])
 	CHECK([[a objectAtIndex: j++] isEqual: @""])