external variable

I want to be able to declare a global variable in a header/source file and then use it in some other source file which has #included it, like

Code:

sth1.c
-----------
int integer;


sth2.c
----------
#include <stdio.h>
#include <sth1.c>

char* main ()
{
	ineger = 45;
	printf("%d", integer);

	return "o-|-<";
}

I looked around in some files like errno.h and could find the "extern" keyword plus other crazy stuff like _RTLENTRY, _EXPFUNC and _UNDERSCOREZZ.
I looked around some and it seemed to me that extern does what I want, but it didn't work. I would get

Code:

Error: Unresolved external '_integer' referenced from sth.obj

Compiler: bcc32 5.6.1

Code:

sth1.c
-----------
int integer;


sth2.c
----------
#include <stdio.h>
#include <sth1.c>
/*AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH*/
char* main ()
{
	ineger = 45;
	printf("%d", integer);

	return "o-|-<";
}

It is int main(). You will have to extern integer

In your header file (an .h file), which is included in C files, put the declaration:

Code:

extern int test;

In one C file put the variable definition:

Code:

int test;

Do not include one .c file in another.

http://www.eskimo.com/~scs/C-faq/q1.7.html

Oh, so that's it. I had put 'extern' in a .c-file.

No you put an extern in a .h file
something like this

Code:

.h file
--------------------------------------
extern integer;

.c file1
--------------------------------------
#include <stdio.h>
#include <sth1.c>
int main ()
{
	ineger = 45;
	printf("%d", integer);

	return 0;
}

.c file2
--------------------------------------
int integer;

integer (integer is not an appropriate variable name anyway).

And you need a type here:

Code:

extern integer;

->

Code:

extern int integer;

Originally Posted by anonytmouse

integer (integer is not an appropriate variable name anyway).

Why? It isn't a reserved keyword.


Quzah.

Originally Posted by quzah

Originally Posted by anonytmouse

integer (integer is not an appropriate variable name anyway).

Why? It isn't a reserved keyword.
Quzah.

I would say that using a type name as a variable name is confusing and not good style. It is also a common typedef. However, it is a style issue, so to each his own.

Originally Posted by anonytmouse

It is also a common typedef.

Now that is evil. Yet another reason for me to abhor typedefs.

True. You didn't say it was illegal, so I'l give you that. I agree, it isn't a very good lable for a variable. Generally speaking, they should be meaningful. I really just wanted to get you to explain to them why it wasn't a good idea. Mainly because I'm usually pedantic, and bored.


Quzah.

Originally Posted by Dave_Sinkula

Now that is evil. Yet another reason for me to abhor typedefs.

What's wrong with typedefs?