multiple definition??

I keep getting this error when I try to compile three files at once:
gcc table.h table.c tabletest.c

tabletest.c:5: warning: return type defaults to âintâ
tabletest.c: In function âmainâ:
tabletest.c:10: warning: unused variable âpâ
/tmp/ccIOnFbt.o: In function `newTable':
/home/cc/cs61cl/fa09/class/cs61cl-bo/hw3/table.c:23: multiple definition of `newTable'
/tmp/ccwhxUwU.o:/home/cc/cs61cl/fa09/class/cs61cl-bo/hw3/table.c:23: first defined here
collect2: ld returned 1 exit status

table.h

Code:

---

struct table;
       
struct table *newTable ( );

---

table.c

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include "table.h"

struct table {
      int entrycount;
}myTable;
       
/* returns an empty table */
struct table * newTable ( ) {
    //struct table * table1 = malloc(sizeof(struct table));
      myTable.entrycount = 0;
      return &myTable;     
 }

---

tabletest.c

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include "table.c"

main() {

    struct table t;
    t.entrycount = 1;
    struct table *p = newTable();
    printf("new address %d\n", p);
    return 0;

}

---

Sorry if this is a really obvious error, but I have a pretty simple header set up, but why is it not compiling? Thanks in advance.

1. You don't generally #include .c files. You include header files, and compile and link .c files.
2. Why do you have "struct table;" in your header? What are you trying to do there?


Quzah.

ok I fixed the table.c --> table.h but now I'm getting a "storage size of t isn't known" for the line "struct table t" in my tabletest.c

I thought I had to put the struct table; line in the header because I'm defining it too in the table.c?

Code:

---

/* table.h */
struct mytable
{
    ...stuff...
};

void myfunction( void ); /* prototype */

/* table.c */
#include<stuffineed.h>
#include"table.h"

void myfunctionprototype( void ) /* actual function */
{
    ...do stuff, presumably stuff that requires our structure...
}


/* somethingelse.c */
#include<stuffineed.h>
#include"table.h"

...

insomefunction()
{
    ...doing stuff...
    myfunction( ); /* can access this because it's a prototype in a header i've included... */

}

---

That's generally how it works.


Quzah.

ah ok that's what I'd thought. thanks for your help!