Creating a FAT Filename Conversion Plug-in

This section describes how to create a FAT Filename Conversion plug-in DLL.

Context

The flowchart below shows the steps to create a Fat Filename Conversion plug-in DLL.

Note: To create the plug-in DLL, the unicodeconv.cpp file is needed. It provides the functions to convert text between Unicode and a foreign encoding.

This tutorial uses the example of CP1250 to explain the process of creating a plug-in DLL.

Prerequisites

This tutorial assumes that you have an understanding of the following:

FAT Filename Conversion Plug-ins Overview introduces Windows code page and the main purpose of the Plug-ins component.

Steps

Create a source file using a text editor and save it as, for example d:\charconvfiles\data\cp1250.txt. This file contains pairs of hexadecimal numbers. The first number in each pair is the encoding of a character in CP1250 and the second is the Unicode encoding of the same character.
Example:
```
...
0x00    0x0000    #NULL
0x01    0x0001    #START OF HEADING
0x02    0x0002    #START OF TEXT
0x03    0x0003    #END OF TEXT
0x04    0x0004    #END OF TRANSMISSION
0x05    0x0005    #ENQUIRY
0x06    0x0006    #ACKNOWLEDGE
...
```
The source file has the same syntax as a cnvtool source file. For more information about the syntax, refer to Cnvtool Source File.
Start a command prompt to run the ConversionTable tool on the source as follows:
cd d:\Symbian\epoc32\tools
ConversionTable.pl d:\charconvfiles\data\cp1250.txt
This process generates a C++ source code file called cp1250.cpp. It is referred to as the ConversionTableTool-generated cpp file, which contains the data structure. The data structure is used by unicodeconv.cpp for the encoding conversion.

Create an mmp file which is used to build the plug-in DLL.

Example:

TARGET            cp1250.dll
CAPABILITY            All
TARGETTYPE            dll

UID        0x100039e6 0x10206A9C
VENDORID     0x70000001

OS_LAYER_SYSTEMINCLUDE
USERINCLUDE            ../inc

SOURCEPATH            ../src
SOURCE            unicodeconv.cpp

SOURCEPATH            +/build/generated/fatcharsetconv
SOURCE            cp1250.cpp

DEFFILE             fatCnv.def

LIBRARY            euser.lib

SMPSAFE

Next actions

Build the plug-in DLL and install it into the \sys\bin\ directory. The DLL is then available to be loaded and called by the File Server.

Related tasks

Using a FAT Filename Conversion Plug-in