reading in a file c small error big problems - c

Question

I am trying to fill 2 matrices from 2 data text files but the compiler is telling me I have conflicting types for the "infiles" (1&2) but if I take out FILE I get a casting error and if I take out infile =fopen i get no output at all for matrices but it does compile. nothing seems to work right
the problem code:
FILE *infile1;
FILE *infile2;
*infile1 = (int)fopen("m1.dat","r");
*infile2 = (int)fopen("m2.dat","r");
full code:
#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <pthread.h>
#define M 4
#define K 4
#define N 4
void *runner(void *param); /* the thread */
int A [M][K];
int B [K][N];
int C [M][N];
struct v {
int i; // row
int j; // column
};
int main(int argc, char *argv[]) {
//using namespace std;
//ifstream infile1 ("m1.dat");
//ifstream infile2 ("m2.dat");
int infile1 = (int)fopen("m1.dat","r");
int infile2 = (int)fopen("m2.dat","r");
FILE *infile1;
FILE *infile2;
//if (!infile1) //testing files
// cerr << "Error: could not open input file 1\n";
//if (!infile2) //testing files
//cerr << "Error: could not open input file 2\n";
if (!infile1) //testing files
fprintf(stderr, "file 1 missing\n");
exit(1);
if (!infile2) //testing files
fprintf(stderr, "file 2 missing\n");
exit(1);
int i, j, size1, size2 =0;
//infile1 >> size1;
//infile2 >> size2;
fscanf(infile1,"%d",&size1);
fscanf(infile2,"%d",&size2);
float s = (float)size1;
int dim = (int)sqrt(s);
for(i=0;i<M;i++){
for(j=0;j<N;j++){
//infile1 >> A[i][j];
// infile2 >> B[i][j];
fscanf(infile1,"%d",&A[i][j]);
fscanf(infile2,"%d",&B[i][j]);
}
}
for(i=0;i<M;i++){
for(j=0;j<N;j++){
if ((j % dim)==0) printf("\n");
printf("%d \t",A[i][j]);
}
}
printf("\n\n");
for(i=0;i<M;i++){
for(j=0;j<N;j++){
if ((j % dim)==0) printf("\n");;
printf("%d \t",B[i][j]);
}
}
printf("\n\n");
int count = 0;
for(i = 0; i < M; i++) { //column
for(j = 0; j < N; j++) { //row
//Assign a row and column for each thread
struct v *data = (struct v *) malloc(sizeof(struct v));
data->i = i;
data->j = j;
// Now create the thread passing it data as a parameter
pthread_t tid; //Thread ID
pthread_attr_t attr; //Set of thread attributes
//Get the default attributes
pthread_attr_init(&attr);
//Create the thread
pthread_create(&tid,&attr,runner,data);
//Make sure the parent waits for all thread to complete
pthread_join(tid, NULL);
count++;
}
}
//Print out the resulting matrix
for(i = 0; i < M; i++) {
for(j = 0; j < N; j++) {
printf("%d ", C[i][j]);
}
printf("\n");
}
printf("\n \n");
fclose(infile1);
fclose(infile2);
return 0;
}
//The thread will begin control in this function
void *runner(void *param) {
struct v *data = (struct v*)param; // the structure that holds our data
int n, sum = 0; //the counter and sum
//Row multiplied by column
for(n = 0; n< K; n++){
sum += A[data->i][n] * B[n][data->j];
}
//assign the sum to its coordinate
C[data->i][data->j] = sum;
pthread_exit(0);
}
Edit: Latest version of code. Still just outputs nothing to the screen. Even have a printf that should run right before it closes and that doesnt even work. The only thing I did change from a working versiion(it used to do it correctly) was that the things related to the opening of the file were in C++ and I changed it to C. No idea why I don't get any errors though. Here is my latest full code. the output looks like this http://tinypic.com/r/21185u9/9
#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <pthread.h>
#define M 4
#define K 4
#define N 4
void *runner(void *param); /* the thread */
int A [M][K];
int B [K][N];
int C [M][N];
struct v {
int i; // row
int j; // column
};
int main(int argc, char *argv[]) {
FILE *infile1 = fopen("m1.dat","r");
FILE *infile2 = fopen("m2.dat","r");
if (infile1 == NULL) //testing files
//if (!infile1) //testing files
//fprintf(stderr, "file 1 missing\n");
perror("File 1 Missing");
exit(1);
if (infile2 == NULL) //testing files
//if (!infile1) //testing files
//fprintf(stderr, "file 1 missing\n");
perror("File 2 Missing");
exit(1);
int i, j, size1, size2 =0;
fscanf(infile1,"%d",&size1);
fscanf(infile2,"%d",&size2);
float s = (float)size1;
int dim = (int)sqrt(s);
for(i=0;i<M;i++){
for(j=0;j<N;j++){
fscanf(infile1,"%d",&A[i][j]);
fscanf(infile2,"%d",&B[i][j]);
}
}
for(i=0;i<M;i++){
for(j=0;j<N;j++){
if ((j % dim)==0) printf("\n");
printf("%d \t",A[i][j]);
}
}
printf("\n\n");
for(i=0;i<M;i++){
for(j=0;j<N;j++){
if ((j % dim)==0) printf("\n");;
printf("%d \t",B[i][j]);
}
}
printf("\n\n");
int count = 0;
for(i = 0; i < M; i++) { //column
for(j = 0; j < N; j++) { //row
//Assign a row and column for each thread
struct v *data = (struct v *) malloc(sizeof(struct v));
data->i = i;
data->j = j;
// Now create the thread passing it data as a parameter
pthread_t tid; //Thread ID
pthread_attr_t attr; //Set of thread attributes
//Get the default attributes
pthread_attr_init(&attr);
//Create the thread
pthread_create(&tid,&attr,runner,data);
//Make sure the parent waits for all thread to complete
pthread_join(tid, NULL);
count++;
}
}
//Print out the resulting matrix
for(i = 0; i < M; i++) {
for(j = 0; j < N; j++) {
printf("%d ", C[i][j]);
}
printf("\n");
}
printf("\n \n");
printf("program ran");
fclose(infile1);
fclose(infile2);
return 0;
}
//The thread will begin control in this function
void *runner(void *param) {
struct v *data = (struct v*)param; // the structure that holds our data
int n, sum = 0; //the counter and sum
//Row multiplied by column
for(n = 0; n< K; n++){
sum += A[data->i][n] * B[n][data->j];
}
//assign the sum to its coordinate
C[data->i][data->j] = sum;
pthread_exit(0);
}

Answer 1

Your error comes from declaring the return value from the file open function incorrectly.
Instead of using your problem code, use:
FILE *infile1 = fopen("m1.dat","r");
FILE *infile2 = fopen("m2.dat","r");
It declares infile1 and infile2 as pointers to the FILE type with the values properly set depending on how successful the file can be opened. In simple terms, call infile1 and infile2 as file handles.
If you want an integer value as the return value, you can look into the open() function instead of fopen(), but fopen() works well in your case.

Answer 2

If you check the exit status of your edited code, you will find that it is 1 due to exiting after the first file check. In your code you have:
if (infile1 == NULL) //testing files
//if (!infile1) //testing files
//fprintf(stderr, "file 1 missing\n");
perror("File 1 Missing");
exit(1);
Which will run the exit(1) function every time (even if infile1 is OK). You need to properly contain exit within the scope of your check with {...}. e.g.:
if (infile1 == NULL) { //testing files
perror ("File 1 Missing");
exit (1);
}
and the same for infile2. I have not checked the remainder of your code.