#define SIZE 9
struct circ_buff{
char buff[SIZE];
int total = 0;
char *tail;
char *head;
} gsm;
Can anybody tell me how to access "tail" & "head"? Using the variable gsm (gsm should be used as struct variable not as a pointer).
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2 Answers
#define SIZE 9
struct circ_buff{
char buff[SIZE];
int total; /* you can't initialize this here */
char *tail;
char *head;
} gsm;
int main() {
gsm.total = 0;
/* it looks like you're writing a circular buffer, so... set head/tail to the
* start of the buffer
*/
gsm.tail = gsm.buff;
gsm.head = gsm.buff;
/*
* gsm.head++; // increment as you add to the buffer, don't
* // forget to check for overflows
*
* // Other stuff you might want to do (assuming correct boundary checking)
*
* *gsm.head = 'G'; // set current head to 'G'
*
* printf("%c\n", *gsm.head); // print current value of head
*
*/
return 0;
}
gsm.tail[INDEX]
or
*(gsm.tail)
int main(int argc, char **argv)
{
#define SIZE 9
struct circ_buff{
char buff[SIZE];
int total;
char *tail;
char *head;
} gsm;
strcpy(gsm.buff, "ohaiohai");
gsm.tail = gsm.buff;
gsm.head = gsm.buff;
printf("%s\n", gsm.buff);
printf("%s\n", gsm.tail);
printf("%s\n", gsm.head);
putchar(*(gsm.tail));
putchar(gsm.head[1]);
exit(0);
}
output:
$ gcc main.c && ./a.out
ohaiohai
ohaiohai
ohaiohai
oh
