diff --git a/include/File.h b/include/File.h
index eafc1f1d2d6352cd96712d2253efab46bffbc1b0..39bb238ddde4432684368469d32e866bac4b5232 100644
--- a/include/File.h
+++ b/include/File.h
@@ -114,6 +114,9 @@ public:
 
     ///  Count the number of string lines into a text file.
     long getNumberOfStringLines();
+    
+    ///  The dimension of the file
+    dword fsize();
 
     static dword byte_read;
 
diff --git a/include/InputFile.h b/include/InputFile.h
index 0697cf010c1e657a496a4fbe727094c90433f9af..fe9abb26b442ba86523395f197e3b7b63b492f16 100644
--- a/include/InputFile.h
+++ b/include/InputFile.h
@@ -35,16 +35,18 @@ public:
 
     virtual bool open( char** parameters ) throw(PacketExceptionIO*);
 
-     virtual void close() throw(PacketExceptionIO*);
+    virtual void close() throw(PacketExceptionIO*);
 
     virtual ByteStreamPtr readByteStream(dword n_byte) throw(PacketExceptionIO*);
 
-     virtual char* readString() throw(PacketExceptionIO*);
+    virtual char* readString() throw(PacketExceptionIO*);
 
     virtual int getType()
     {
         return 0;
     };
+    
+    virtual dword setpos(dword offset) throw(PacketExceptionIO*);
 
 protected:
 
diff --git a/include/OutputFile.h b/include/OutputFile.h
index bf0e98ba30a6a4a3d28876ae5f7b37557c60ae48..d53d4259eaf23a689936fd0ca801e911e00f16c2 100644
--- a/include/OutputFile.h
+++ b/include/OutputFile.h
@@ -36,6 +36,8 @@ public:
 
     virtual void close() throw(PacketExceptionIO*);
 
+	///first parameter: filename
+	///second parameter: fopen modes: w, r, a (optional)
     virtual bool open(char** parameters) throw(PacketExceptionIO*);
 
     virtual bool writeByteStream(ByteStreamPtr b) throw(PacketExceptionIO*);
diff --git a/src/File.cpp b/src/File.cpp
index 4c51abb0640a54e4d8420a2403bae930bb91f400..c8616458297cb290c5b3b434ae53a9621bf6b0ed 100644
--- a/src/File.cpp
+++ b/src/File.cpp
@@ -345,3 +345,18 @@ bool File::writeByteStream(ByteStreamPtr b) throw(PacketExceptionIO*)
     return true;
 
 }
+
+dword File::fsize(){
+	if(closed)
+		return 0;
+		
+    long prev=ftell(fp);
+    if(prev == -1L)
+    	return 0;
+    fseek(fp, 0L, SEEK_END);
+    long sz=ftell(fp);
+    if(sz == -1L)
+    	return 0;
+    fseek(fp,prev,SEEK_SET); //go back to where we were
+    return sz;
+}
diff --git a/src/InputFile.cpp b/src/InputFile.cpp
index 8176966f07e2b5abe376ed0aa55d55d7383a00aa..2e15db016434b91b0de0eb208d7db931089257ec 100644
--- a/src/InputFile.cpp
+++ b/src/InputFile.cpp
@@ -74,3 +74,7 @@ char* InputFile::readString() throw(PacketExceptionIO*)
     eof = file->isEOF();
     return c;
 }
+
+dword InputFile::setpos(dword offset) throw(PacketExceptionIO*) {
+	return file->setpos(offset);
+}
diff --git a/src/OutputFile.cpp b/src/OutputFile.cpp
index f6a93dbc5109b6088ea099885e09685a6899d354..8725e483f718cacbdc63daf58d58d661c5002e80 100644
--- a/src/OutputFile.cpp
+++ b/src/OutputFile.cpp
@@ -44,7 +44,12 @@ void OutputFile::close()  throw(PacketExceptionIO*)
 
 bool OutputFile::open(char** parameters) throw(PacketExceptionIO*)
 {
-    file->open(parameters[0], "w");
+	if(parameters[1] != 0) {
+    	file->open(parameters[0], parameters[1]);
+    }	
+    else {
+    	file->open(parameters[0], "w");
+    }
     filename = parameters[0];
     isclosed = false;
     return true;