Thread: New Programmer, new Error

Hey guys I'm new to C and relatively new to programming, but I'm getting an error I've never seen before. All my research on this board and online has to do with something called SDL but I dont know what that is, therefore I dont use it....ha.

Anyways my code is below, its a simple linked list(Which i probably botched) and it reads from a file, adds information, and writes to the file again. I havent done the writing part yet, should be cake though.

Yikes I forgot to post the error. lol.
ERROR:
1>Linking...
1>LINK : fatal error LNK1561: entry point must be defined

Also im looking at the fputs function to write, and im thinking that it isnt right because p is a FILE pointer but its set to read. I think I need to initialize and use q for that.

Also does fputs() let me use "" to add \t for formatted file writing?

Example:
John Williams 99.80 Average.



Code is below:

Code:

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct Student{
	float ave;
	char name[128];
	struct Student* next;
}*head = (Student *)malloc(sizeof(Student));

int main()
{
struct Student* curr =(Student *)malloc(sizeof(Student));
float i = 0.0;
int count = 0, x, k;
FILE* p = fopen("studentListInFile.txt","r");
FILE* q = fopen("studentListInFile2.txt", "w");
if (curr == 0){
	printf("out of memory\n"); return -1;}
head->next = NULL;
curr=head;
curr->next = NULL;
while(!feof(p))
{		
		fgets(curr->name, 40, p);
		curr->ave = 0.0;
		curr->next = (Student *)malloc(sizeof(Student));
		curr = curr->next;
		curr->next=NULL;
		count++;

	
}
curr = head;
for (x = 0; x<count; x++)
{		printf("Enter the final average for the student: ");
		scanf("&#37;f", i);
		curr->ave = i;
		curr = curr->next;
}
curr = head;
for(k = 0; k< count; k++)
{
	fputs(curr->name, q);
	fprintf(q, "\t%f\0", curr->ave);
	curr = curr->next;
}
curr=head;
for(x=0;x<count;x++)
{
	free(curr);
	curr = curr->next;
}
free(head);
fclose(p);
fclose(q);
return 0;
}

Ok, now Im confused, is it the struct part? Shouldn't I cast the pointer returned by malloc as the type I would want?

Took out struct and Im still getting an error, so it has to be the whole casting. Im still confused though. Thanks for the help in advance

Ok I took out both struct keywords in the memory allocation and rebuilt the problem in another solution. If I stay in my current solution in VS 2008 i keep getting the same errors even though I had fixed them, can anyone help me with that too?

Ive fixed a LOT of errors in the program, and now I get an error after inputting the first value from the user, it takes me to line 1287 in input.c

#else /* _UNICODE */
_FASSIGN( longone-1, (char*)pointer , pFloatStr, (char)decimal, _loc_update.GetLocaleT());

When i hit the break key in debug mode. Any suggestions?

Ok I think I get what youre saying. I need to append the list. This is where I get confused. Since curr is going to go through the list, wont I need to create a specific named struct for each student in order for the linked list to stay intact?

Im deleting what was stored in curr when I reassign it, so Im defeating myself in the loop. Am I on the right track?


Also i think everytime the while loop goes through Ill be starting at the beginning of the file again with fgets? Am I wrong in that?

{EDIT} Updated code is at the top, thanks for the suggestion itCbitC.


Ok....but shouldnt the list be created as I initialize the next pointer in each struct?

for example

Code:

struct Node{
int data;
Node* next;
}

Should be enough to make a node member of a linked list I create in my main function right? All I would need to do is initialize a head variable, a temp(curr in my case) variable, and then when a new member is to be added on, i assign it to curr, head->next = curr, curr-> next = 0?

Im afraid this boils down to an ignorance of linked lists, and I couldnt find a tutorial for one in your guys' tutorials.

For some reason I keep thinking I have to name each member in the list to solve this problem, even though thatd be ludicrous as the list could be potentially HUGE.

So after reading the linked list tutorial, I think that my program does implement a linked list properly, with a few minor tweaks. It builds fine, but when i run the program in debug mode i get the error previously said.

Does that still have to do with my linked list even though every time I take in a new string I creat a new struct and allocate the memory for it?

Ok, in that initial while loop I'm wrong somewhere. I put break points at the beginning of the for loop to look at what was stored in the variables.

Something is wrong with my condition in the while loop and something is wrong with the way im going through the linked list. Im completely dumbfounded on both accounts.

The name variable in curr has 128 T looking characters and its point to ?? it says. For the double, im getting a memory location as its value, im assuming this is because curr as a whole is a pointer, therefore the variables inside act as such?

Im sorry for my ignorance on this and if theres a place where I can read this info, please, point me there, but currently youre the best source of information on the web.