fnkapp

INTRODUCTION

This is a tutorial on how to include fnkdat in a project using a plain 'ol Makefile. It's certainly not the only way to do it, it's just one way. If, after reading this, you can build and run a simple application that uses fnkdat, then I was successful ;).

SOURCE

The first thing you need to do is make a directory to store the code for this masterpiece. Since the application will be called fnkapp, mkdir fnkapp would seem appropriate. Next cd fnkapp and grab fnkdat.h & fnkdat.c, and save them. Next create a new file named fnkapp.c using your favorite editor, and put the following source in it.

#include <stdio.h>
#include "fnkdat.h"

int main(int argc, char** argv) {

   char buffer[FILENAME_MAX];

   /* STEP #1 */
   if (fnkdat(NULL, NULL, 0, FNKDAT_INIT) < 0) {
      perror("could not initialize fnkdat");
      return 2;
   }

   /* STEP #2 */
   if (fnkdat(NULL, buffer, FILENAME_MAX, FNKDAT_USER) < 0) {
      perror("could not get directory : FNKDAT_USER");
      return 2;
   }
   printf("FNKDAT_USER: %s\n", buffer);

   /* STEP #3 */
   if (fnkdat(NULL, buffer, 0, FNKDAT_UNINIT) < 0) {
      perror("could not uninitialize fnkdat");
      return 2;
   }

   return 0;
}

I'm assuming you're comfortable w/ C, so I'm only going to explain the fnkdat specific steps.

1. The first thing you need to do is initialize fnkdat. This is done by calling fnkdat with the FNKDAT_INIT flag. All other arguments are simply ignored.

2. Next, we use the library. This will store the current user's directory (for this application) in buffer.

3. Next we shutdown fnkdat. You should call this once you're finished using the library.

MAKEFILE

Now it's time to create a Makefile; copy the following text into it.

CFLAGS=-DPACKAGE=\"fnkapp\"

all: fnkapp

check: fnkapp
   ./fnkapp

fnkapp: fnkdat.o fnkapp.o
   $(CC) -o $@ *.o

clean:
   /bin/rm -f *.o fnkapp

This is pretty standard, and the only thing to explain is the extra define in the CFLAFS. The PACKAGE macro has the same purpose as the one generated by autoheader (if you're using autoheader in your project then you can use its output and omit this step). It's used throughout fnkdat in generating directory names. It should uniquely identify your application.

RUN

That's it! Go back to the command line and type make. You should see something along the lines of

cc -DPACKAGE=\"fnkapp\"   -c -o fnkapp.o fnkapp.c
cc -o fnkapp *.o

Now type ./fnkapp and you should see your new application tell you where it would store your user specific settings, if it had any. I see the following:

FNKDAT_USER: /home/djm/.fnkapp/

WEBPAGE

The latest version and additional information, tutorials, and source can be found at http://www.maccormack.net/~djm/fnkdat/