using _countof in arduino

Forum 2005-2010 (read only) Software Syntax & Programs
1

In the following code, I am trying to use the _countof function in arduino. However, it's not working. I was wondering if there is a way to make the following code work in arduino. So basically i need another function that would do the samething as a _countof function.

Anybody's help will be highly appreciated.

 #define PI = 3.14159265358979323846264338327950288
 #include <string.h>
 #include <ctype.h>
 #include <math.h>
 #include <stdlib.h>

char linea[300] = "$GPRMC,023000,A,5000.00,N,01000.00,E,000.5,054.7,141010,020.3,E*68";
                      
char status[2];
char statusA[] = "A";
char statusV[] = "V";
strncpy_s(status,_countof(status), linea +14, 1);

if(strstr(status,statusA)!=NULL)
{
etc.....
}

Well considering that the countof function doesn't work. I was wondering if the stncpy_s and strstr functions will in arduino. I mean I compiled the code after commenting out the _countof function and it didn't really show a compiling error. But just to be on the safe side, I was wondering if stncpy_s and strstr functions will actually do what they are suppose to.

2

#define _countof(x) (sizeof(x) / sizeof (x[0]))

3

Hello,

I'm not a programmer. Could you please reply in a bit more detail.

I have a char string called "linea" from the GPS, declared as:

char linea[300] = "$GPRMC,023000,A,5000.00,N,01000.00,E,000.5,054.7,141010,020.3,E*68";

Then I have another char declared as: char status[2];

Now using the _coutof function I want to go 14 character counts ahead on the linea string and copy 1 value, which happens to be "A", into the status char using the strstr function. I coded this part as:

strncpy_s(status,_countof(status), linea +14, 1);

This works just fine in C, but how can I adapt it into Arduino?

The #define _countof(x) (sizeof(x) / sizeof (x[0]))
should I define that at the top with all the other libraries?
what's x and x[0]?

Please help!

4

"x", as always, is the unknown.
Like "status".

(Where does the constant 14 come from?)