Problem reading/printing Data

[Gamma_123]

I wrote following code for reading Data and storing it on an array.

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define MAX_L 100




int read(double *arr, int size, char *filename);
int read(double *arr, int size, char *filename)
{
int z;
FILE *infile;
infile = fopen(filename,"r");


if (infile==NULL)
    {perror("Error");
    return 0;
    }


for(z=0;;z++)
    {
    if(fscanf(infile,"%lf",&(arr[z]))==EOF || z>MAX_L)break;
    
    }
return z;
}


//void Print(double *arr, int length);
void Print(double *arr, int length)
{
int i;
for(i = 0;i<length;i++)
    {
    printf("A[%d]: %d\n",i,arr[i]);
    }
}




int main()
{
double f[MAX_L];
int r;
r = read(f, MAX_L, "Points.dat");
Print(f,lesen);
}

It compiles without problems, however it only prints zeros. Can anybody give me a hint what the problem might could be?
Thanks!

[jimblumberg]

It compiles without problems, however it only prints zeros.

Perhaps you should increase your compiler warning level and fix all warnings and errors?

main.c||In function ‘read’:|
main.c|11|warning: unused parameter ‘size’ [-Wunused-parameter]|
main.c|36|warning: no previous declaration for ‘Print’ [-Wmissing-declarations]|
main.c||In function ‘Print’:|
main.c|42|warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘double’ [-Wformat=]|
main.c||In function ‘main’:|
main.c|54|error: ‘lesen’ undeclared (first use in this function)|
main.c|54|note: each undeclared identifier is reported only once for each function it appears in|
main.c|52|warning: variable ‘r’ set but not used [-Wunused-but-set-variable]|

[Guest]

Line #38

printf("A[%d]: %d\n",i,arr[i]); // You tell printf to expect two integers, but arr[] contains doubles

You should really enable compiler warnings and learn to indent your code properly.

[Gamma_123]

Thank you very much! Lien #38 was the problem. Can you pleas tell me how to increas my compiler warning level?

[jimblumberg]

What compiler/IDE are you using?

[Gamma_123]

gcc (GCC) 5.3.0

[userxbw]

are you even adding

 -Wall

to the line?

here are a few more

Using the GNU Compiler Collection (GCC): Warning Options

[Guest]

gcc (GCC) 5.3.0

I recommend adding the flags -Wall -Wextra -pedantic for good coverage, especially while you're still learning.

[Gamma_123]

How can I enable these flags? By typing in -Wall, I get the error that the comand is either wrong spelled or couldn't be found.

[userxbw]

How can I enable these flags? By typing in -Wall, I get the error that the comand is either wrong spelled or couldn't be found.

how are you compiling your program, command line or IDE?