Create two pointers, each set to the start of the list.
Update each as follows:

while (pointer1) {
 pointer1 = pointer1->next;
 pointer2 = pointer2->next; if (pointer2)
pointer2=pointer2->next;
 if (pointer1 == pointer2) {
   print (\"circular\n\");
 }
}

If a list is circular, at some point pointer2 will wrap
around and be either at the item just before pointer1, or
the item before that. Either way, it?s either 1 or 2 jumps
until they meet.

start = pointer;

while(pointer)
{ 
  if(pointer->next == start)
     printf("Circular");
   pointer = pointer->next;
}
printf("Non-Circular");

consider home pointer as the starting pointer of the linked 
list.
consider temp as the temporary pointer.


temp = home;
while(temp != NULL)
{
    if(temp -> next == start)
    {
           flag = 1;
           break;
    }
    else 
           flag = 0;
temp = temp -> next;
}

if(flag == 1)
   printf("Circular");
else
   printf("Not circular");