Using a dylib file in XCode

main.dylib is the exported library. shownow is the exported method in main.dylib.

int main (int argc, const char * argv[]) {

char* lib_name = "./main.dylib";

void* lib_handle = dlopen(lib_name, RTLD_NOW);

if(lib_handle)

{

void (*shownow)(void) = dlsym(lib_handle, "shownow");

if(shownow)

{

shownow();

}

}

return 0;

}

Creating a dylib file in XCode

!--main.c file

#define EXPORT __attribute__((visibility("default")))

__attribute__((constructor))

static void initializer(void)

{

printf("%s",__FILE__);

}

__attribute__((destructor))

static void finalizer(void)

{

printf("%s",__FILE__);

}

EXPORT

void shownow (void) {

// insert code here...

printf("Hello, World!\n");

}

Use EXPORT before any funtion that you would like to export in dylib file. After you have written the file. You can create a dylib in terminal by typing the command below.

Locate the main.c file and type

gcc -dynamiclib -std=gnu99 "FileName" -current_version 1.0 -compatibility_version 1.0 -fvisibility=hidden -o "LibFileName"

Example:

"FileName" - main.c

"LibFileName"- main.dylib

C++ code to make your application a trial version

{

time_t rawtime, end;

struct tm * endinfo;

double dif;

time ( &rawtime );

endinfo = gmtime ( &rawtime );

endinfo->tm_year = year-1900;

endinfo->tm_mon = Month-1;

endinfo->tm_mday = Day;

end = mktime ( endinfo );

dif = difftime(end, rawtime);

if (dif less than 0)

printf("\nTrial Version Expired \n");

}

Year, Month and Day are all integers. Enter your Date on which you want the application to be expired.

OpenCV setup in MAC OSX

Install macports - > http://www.macports.org/install.php

Open terminal type sudo port -v selfupdate

type sudo port install opencv

Once the installation is successful. Include OpenCV in XCode by following the steps below.

These instructions were written for Xcode 3.1.x

• Create a new XCode project using the Command Line Utility/Standard Tool template

• Select Project -> Edit Project Settings

• Select the Build tab

• Set Configuration to All Configurations

• In the Architectures section, double-click Valid Architectures and remove all the PPC architectures

• In the Search Paths section set Header Search Paths to /usr/local/include/opencv

• Close the Project Info window

• Select Project -> New Group and create a group called OpenCV Frameworks

• With the new group selected, select Project -> Add to Project…

• Press the "/" key to get the Go to the folder prompt

• Enter /usr/local/lib

• Select libcxcore.dylib, libcvaux.dylib, libcv.dylib, libhighgui.dylib, and libml.dylib.

• Click Add

• Uncheck Copy Items… and click Add

Now you should be able to include the OpenCV libraries, compile, and run your project