Use another language to call a function: Difference between revisions

This is a restatement of the problem, it is not a solution. Please remove it.

I rewrote the driver as

<lang c>#if 0

I rewrote the driver according to good sense, my style,

and discussion --Kernigh 15:45, 12 February 2011 (UTC).

This is file main.c on Autumn 2012 ubuntu linux release.

The emacs compile command output:

-*- mode: compilation; default-directory: "/tmp/" -*-

Compilation started at Mon Mar 12 20:25:27

make -k CFLAGS=-Wall main.o

cc -Wall -c -o main.o main.c

Compilation finished at Mon Mar 12 20:25:27

#endif

#include <stdio.h>

#include <stdlib.h>

extern int Query(char*Data,unsigned*Length);

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

char Buffer[1024], *pc;

unsigned Size = sizeof(Buffer);

if (!Query(Buffer,&Size))

fputs("failed to call Query",stdout);

else

for (pc = Buffer; Size--; ++pc)

putchar(*pc);

putchar('\n');

return EXIT_SUCCESS;

}

</lang>

With solution

<lang c>

#if 0

This is file query.c

-*- mode: compilation; default-directory: "/tmp/" -*-

Compilation started at Mon Mar 12 20:36:25

make -k CFLAGS=-Wall query.o

cc -Wall -c -o query.o query.c

Compilation finished at Mon Mar 12 20:36:26

#endif

#include<string.h>

int Query(char*Data,unsigned*Length) {

char*message = "Here am I";

unsigned n = strlen(message);

if (n <= *Length)

return strncpy(Data,message,(size_t)n), *Length = n, 1;

return 0;

}

</lang>

And finally, excitement!

<lang bash>$ gcc main.c query.o -o main && ./main

Here am I

$

</lang>