How to call a static function - c

Question

I'm trying to call the following function
In daydream.c :
.....
static int create_new_account(void)
{
DDPut(sd[newucstr]);
switch (HotKey(HOT_NOYES)) {
case 1:
if (CreateNewAccount()) {
clog.cl_userid = user.user_account_id;
clog.cl_firstcall = user.user_firstcall;
clog.cl_logon = time(0);
if (user.user_connections == 0)
clog.cl_flags |= CL_NEWUSER;
clog.cl_bpsrate = bpsrate;
getin();
return 1;
}
return 0;
case 2:
DDPut("\n");
return 0;
default:
return 1;
}
}
From matrix.c:
int apply()
{
create_new_account();
}
However, it won't compile link:
matrix.o: In function `apply':
matrix.c:(.text+0xf0): undefined reference to `create_new_account'
collect2: error: ld returned 1 exit status
make: *** [daydream] Error 1
So, my question is, how do I call this function properly?

Answer 1

You must not know what the keyword static means. static keeps create_new_account global to daydream.c only. Nobody else can access it. If you want other functions to access it:
Remove the keyword static and extern this function into matrix.c.
Option 1:
/* daydream.c */
int create_new_account(void)
{
...
}
/* matrix.c */
extern create_new_account(void);
Option 2:
/* daydream.c */
int create_new_account(void)
{
....
}
/* daydream.h */
extern int create_new_account(void);
/* matrix.c */
#include "daydream.h"
Create a external wrapper function to call that in turn calls your static function.
/* daydream.c */
static int create_new_account(void)
{
...
}
int create_new_account_wrapper(void)
{
return create_new_account();
}
/* matrix.c */
int apply(void)
{
return create_new_account_wrapper();
}
My preference is answer 1, option 2.