How do I declare a FILE in C?

Question

Good morning.
I'm coding in C for a school project and i keep facing this error in the functions.h where i type

#ifndef FUNCTIONS_H_INCLUDED 
#define FUNCTIONS_H_INCLUDED
#define DIMID 4
#define COO 2
#define DIM 20

FILE *data1;
FILE *data2;
FILE *out;

It always gives the error message:

"error: FILE does not name a type"

These Files are used throughout the code but as an example I show 2 bellow

void comandp(cellphone *tel1,read *read,FILE *out);
void infected(cellphone *head,read *read,FILE *out);

Where it returns the error message:

"Error: 'File' has not been declared"

Does anyone have any clue as to what I'm doing wrong and how to fix this issue?
Thank you so much

Note that you are also using the conditional preprocessor directive without a `#endif`. Look at https://www.cprogramming.com/reference/preprocessor/ifndef.html. If you are beginning to learn C, I really suggest you go check out the first five classes of the Harvard CS50 course that is on youtube. C is a bit tricky and it's better to start with solid foundations or it will feel like you are fighting it all the time. — cassepipe, Jan 20 '21 at 14:00
I already know C, and the #endif was at the bottom at the bottom of the code. As it turns out i was forgetting to do #incluude. Thank you though :) — Rodrigo Oliveira, Jan 20 '21 at 14:16

score 2 · Answer 1 · answered Jan 20 '21 at 13:53

2

You will need to include the library header #include <stdio.h> if you wish to use the inherent structure of FILE or create the structure of FILE in another location.

answered Jan 20 '21 at 13:53

KillaBytes

447
3
10

1

Thank you so much!! – Rodrigo Oliveira Jan 20 '21 at 14:15

How do I declare a FILE in C?

1 Answers1