PureBasic Forums - English

Posted: **Sun Jul 25, 2004 4:30 pm**

I am trying to learn more about C and am fiddling withe the very simple test.c from the \LccWin32 directory. Most of interest for me is this function at the moment:

Code: Select all

extern _stdcall char *PB_StringMultiply(char *String, int NbTimes)
{
  char *ResultString = PB_StringBase;
  int   k;

  if (String && *String)  // It's always good for safety and perfomance to exclude null or empty strings
  {
    int StringLength = strlen(String);

    for (k=0; k<NbTimes; k++)
    {
      strcpy(PB_StringBase, String);
      PB_StringBase += StringLength;  // Increase the output string buffer
    }
  }

  *PB_StringBase = 0;     // Finally write the zero ending string. PB_StringBase contains the result string

  return ResultString;    // Returns the start of the buffer, as it has been passed
}

and while I understand the code itself, I got a rough time using/calling it.

What I am trying to do is to add it to the main function

Code: Select all

int main()
	{
		PB_MessageBox(0, "Titre", "Text", 0);
		return 0;
	}

along the line "output the result in the message box" but anytime I execute it, it crashes.

Basically I got two questions:

1. Anyone knowing a good book about C, preferably online, with some nice examples on pointers and string handling?

2. Is there any special difference between a C function for use in another C source and a C function that is written for PureBasic? How would I need to call the PB_StringMultiply from C?

Thanks; I know my request is along the line "enlighten me".

Posted: **Sun Jul 25, 2004 7:00 pm**

a couple of downloadable books.
http://steamedpenguin.com/download/books/

online.
http://rcamera.org/cgi-bin/eng.cgi?c-string.article
http://laurel.datsi.fi.upm.es/~ssoo/C/CE.html
http://www.dgp.utoronto.ca/~neff/teachi ... intro.html
http://computer.howstuffworks.com/c14.htm
http://www.flipcode.com/tutorials/
http://www.harpercollege.edu/bus-ss/cis ... 01/l01.htm

Posted: **Sun Jul 25, 2004 9:59 pm**

2 - There are no majors differences between a call to a C function from C/C++ or from PureBasic.

Posted: **Sun Jul 25, 2004 10:05 pm**

Thanks, guys.

Posted: **Sun Jul 25, 2004 10:52 pm**

If you are testing your library examples from some C main() function then you need to make sure you have all the PB global variables initialised to something sensible for your code (e.g. the PB_StringBase in your case should point to e.g. a 64k block of memory that you have allocated, to make it similar to what woud happen in PB programs).

Posted: **Sun Jul 25, 2004 11:09 pm**

Thanks! Very good pointer!

Posted: **Mon Jul 26, 2004 8:46 am**

jack wrote:a couple of downloadable books.

Thanks for those links, Jack. Just starting to wade into the DL books, and the info seems pretty useful, some aha info useful even outside c, c++

Posted: **Mon Jul 26, 2004 9:16 am**

Yep, very good!

I managed to get running what I wanted to! Together with the site about strings in C, tinman's hint did it!

PureBasic Forums - English

Library SDK C example

Library SDK C example