help with struct

hello guys,
i have been thinking of my college project work given to me. where in one sutitation i was suppose to check where a structure is empty are not. for instance

Code:

struct something
{
     int something1;
     int something2[20];
};


int main()
{
       struct something some[10];

      if(how do i check that some[1] struct variable is empty)
}

is there any way that i can check that.

i got one more thing to be clarified about strtok fucntion, lets take an example

Code:

#include <stdio.h>
#include <string.h>

int main()
{
    char str[]= {"This is a test string"};
    char *p;
    
    p=strtok(str," ");
    while(p != NULL)
    {
        printf("Token : %s\n",p);
        p=strtok(NULL," "); 
    }
    printf("The original string \" %s \"",str);
    
    getchar();
    return 0;
}
/*my ouput
Token : This
Token : is
Token : a
Token : test
Token : string
The original string " This "
*/

if u look at that code the first call to function strtok is with the orginal string 'str' and with the second call i am sending the update pointer NULL as a parameter. and at the end i wanted to print the original string of 'str'. but after using strtok my original string is changed which just contains the first word. is there any way that i can get back that string. well i thought of one way that's copy the original string to some other string before the sending the orginal string to strtok.

well, it might me simple thing which might have confused me a lot, can any one explain this please

ssharish2005

if(how do i check that some[1] struct variable is empty)

Check all members for zero (or whatever it was initialized to), and strings for "".

When you declare a struct as an automatic variable (inside a function), it's filled with undefined values unless you initialise it. There's no such concept as "empty". Initialise the struct to some sentry values (perhaps 0), and use that to denote "empty".

As for strtok, it will always put nulls into your string. Make a copy if you want it untouched.

Code:

p=strtok(str," ");

That's not how you use strtok(). At least, I don't think it is.

[edit]
Yes it is; sorry. http://faq.cprogramming.com/cgi-bin/...&id=1044780608
[/edit]

well, the best way that i can keep original string safe is just have a copy of it. as crw says.

ssharish2005

To keep the original string unmodified, consider using strcspn or sscanf instead of using strtok.

thax very my DAVE is got sorted

ssharish2005