reading.c

/* Part of a program that read a file. */

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

int main() {
    FILE *mainfile;
    mainfile = fopen("texto.txt", "r+");
    if (mainfile == NULL) { printf("ERROR"); }
    else { printf("OK"); }

    unsigned char string[100][10001];    // [line break][letters]
    int qnt;    // amount of line break
    int f, f2;    // any use (for)


    for (qnt = 0; qnt < 100; qnt++) {
        printf("\n=== Point ===");    // the error happens after "=== point ==="
        fgets(mainfile, 9999, string[qnt]);
/*
The compiler compiles, but also presents these two errors:
   [Warning] passing arg 1 of `fgets' from incompatible pointer type
   [Warning] passing arg 3 of `fgets' from incompatible pointer type
*/
        for (f = 0; f < 9999; f++) {
            printf("\n> %d", f);
                if (string[qnt][f] == 255) { goto goto_EOF; }
                if (string[qnt][f] == '\0') { break; }
        }
    }
goto_EOF:
(...) }

RUN:

>>> OK.
>>> === Point ===

The program crashes <<<

:END