Hello -World Example: Using P.I.P.S.

This example application shows a simple EXE and DLL written using P.I.P.S. -(P.I.P.S. Is POSIX on Symbian Platform). It also shows the dynamic lookup -of symbols by name mechanism used in Unix-like operating systems, instead -of the native Symbian Platform lookup by ordinal mechanism. P.I.P.S., from -Symbian OS v9.3, provides APIs from libdl library to -implement this lookup by name mechanism.

The example defines a simple DLL using the P.I.P.S. STDDLL target -type, with an exported function. It also creates a simple EXE, using the STDEXE target -type, which calls the DLL's exported function using the lookup by name mechanism. -These P.I.P.S. specific target types are required to enable the specific options -for compilers and linkers to generate P.I.P.S. executables and to make symbol -information available in the executable image.

Download

Click on the following link to download -the example: HelloWorldExample.zip

Click: browse to view the example code.

Description

The following sections provide more -information about the example.

Creating a simple DLL using P.I.P.S. -STDDLL target type

The example creates a DLL file that declares -and defines an exported function. The target type of this DLL file is STDDLL. -It contains a header and a source file:

helloworlddllexample.h: -this declares a function with external linkage. Note that for a STDDLL library, -functions and data with external linkage are exported by default, without -any requirement for IMPORT_C and EXPORT_C declarations -in header or source files.
helloworlddllexample.cpp: -this defines the function declared in the header file, which displays a hello -world message to the console.

Creating a simple EXE using P.I.P.S. STDEXE target type

The -example creates an EXE file which calls the exported function of the loaded -DLL. The target type of this EXE file is STDEXE. It calls -the following libdl functions to use the lookup by name -mechanism:

dlopen(): -This function is used to load the DLL file which contains an exported function.

dlsysm(): -This function gets the address of a symbol defined within the DLL loaded by -the dlopen() call.

dlclose(): -This function informs the system that the DLL loaded by a previous dlopen() call -is no longer needed by the application.

dlerror(): -This function is used to get the last error that occurred from any of the libdl APIs.

The EXE links to libdl.lib to use these functions.

Build

The Symbian -build process describes how to build this example application.

The HelloWorldExample builds -two files, a DLL file helloworlddllexample.dll, and an -EXE file helloworldexeexample.exe, in the standard locations.

To -run the example, start helloworldexeexample.exe from -the file system or from your IDE. After launching the executable, depending -on the emulator you are using, you may need to navigate away from the application -launcher or shell screen to view the console.

+ + + + + +Hello World Example: Using P.I.P.S. +

This example application shows a simple EXE and DLL written using +P.I.P.S. (P.I.P.S. Is POSIX on Symbian Platform). It also shows the +dynamic lookup of symbols by name mechanism used in Unix-like operating +systems, instead of the native Symbian Platform lookup by ordinal +mechanism. P.I.P.S., from Symbian OS v9.3, provides APIs from libdl library to implement this lookup by name mechanism.

The example defines a simple DLL using the P.I.P.S. STDDLL target type, with an exported function. It also creates a simple +EXE, using the STDEXE target type, which calls the +DLL's exported function using the lookup by name mechanism. These +P.I.P.S. specific target types are required to enable the specific +options for compilers and linkers to generate P.I.P.S. executables +and to make symbol information available in the executable image.

Download

Click on the following link to +download the example: HelloWorldExample.zip

Click: browse to view the example code.

Description

The following sections provide +more information about the example.

Creating a simple +DLL using P.I.P.S. STDDLL target type

The example creates +a DLL file that declares and defines an exported function. The target +type of this DLL file is STDDLL. It contains a header +and a source file:

helloworlddllexample.h: this declares a function with external linkage. Note that for a STDDLL library, functions and data with external linkage +are exported by default, without any requirement for IMPORT_C and EXPORT_C declarations in header or source files.
helloworlddllexample.cpp: this defines the function declared in the header file, which displays +a hello world message to the console.

Creating a simple EXE using P.I.P.S. STDEXE target type

The example creates an EXE file which calls the exported +function of the loaded DLL. The target type of this EXE file is STDEXE. It calls the following libdl functions to use the lookup by name mechanism:

dlopen(): This function is used to load the DLL file which contains an exported +function.

dlsysm(): This function gets the address of a symbol defined within the DLL +loaded by the dlopen() call.

dlclose(): This function informs the system that the DLL loaded by a previous dlopen() call is no longer needed by the application.

dlerror(): This function is used to get the last error that occurred from +any of the libdl APIs.

The EXE links to libdl.lib to use these +functions.

Build

The HelloWorldExample builds two files, a DLL file helloworlddllexample.dll, and an EXE file helloworldexeexample.exe, +in the standard locations.

To run the example, start helloworldexeexample.exe from the file system or from +your IDE. After launching the executable, depending on the emulator +you are using, you may need to navigate away from the application +launcher or shell screen to view the console.

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