OK. I am not too sure what you are asking.

I think you want to share data between two programs?

If so I would would write the data into a file and save it.

Then the other program can read the data out of the file.

I think that is easiest.

I think I did a similar thing, but the same program used the data but it could have been a
different program.

It worked very well and is effient and easy, you put the data into a structure and save
it, then read it back.

In this case the data is an array of a structures.

The good thing is you can change the structure and it still works.

It is a great bit of code as it does so easilly and is blindly fast :O)

It will read in about 6 magabytes in seconds, or less than a second.

It is not clear if both programs will be runniing at the same time from your question,
in which case you might need to coordinate the writing and the reading of the data.

If that is the case the errno bit might help, it probably will return an error if the file
is curently being written to I would imagine.

Code:
// you might need some of these header files
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <io.h>
#include <fcntl.h>
#include <errno.h>


#define MAXLIST 30000






FILE  *dataptr;

typedef struct {
			char name[40];		
			float stack;	
			float dolstack;
			float tempval;
			int pfr;
			float tempstack;
			} PLYR;
			
PLYR pname[MAXLIST]; // an array of structures called pname





datasave(){

		if (	(dataptr=fopen("data.doc", "wb+" )) != NULL) {
				fwrite(  pname, sizeof( pname   ), 1, dataptr);
				fclose(dataptr);
			
		}
		else {
			printf("\n error %d", errno); // not needed
			puts("\nCant creat datafile");
			exit(2);

		}
	

}

dataread(){

		if (	(dataptr=fopen("data.doc", "rb" )) != NULL) {
			fread(  pname, sizeof( pname   ), 1, dataptr);
			fclose(dataptr);
			
		}
		else {
			printf("\n read errorerror %d", errno); // not needed
			puts("\nCant read datafile");
			exit(2);

		}

}
So one the first program would use datasave and the second program would use dataread.

You don't need the errno stuff (probably).

It is even easier if it is a single structure, you could make your array size 1 (MAXLIST)
if you have a single structure and then use the same code.