Thread: Placing #'s from a file into an array

You could always just use the search button. Oh, and perhaps read the FAQ on reading from a file.


Quzah.

Use int*array, realloc(), free(), and fscanf().

Something like this:

Code:

#include <stdlib.h>  /* for realloc(), free() */

int *array, x, *p;
size_t arraylen = 0, n;

while(fscanf(fp, "%i", &x)) {
    p = realloc(array, (arraylen+1));
    if(!p) {
        free(array);
        perror("Out of memory");
        exit(1);
    }
    array = p;

    array[arraylen++] = x;
}

for(n = 0; n < arraylen; n ++) {
    printf("%i ", array[n]);
}

free(array);

You're allocating bytes, but storing integers. You might want to fix that.


Quzah.

> int *array, x, *p;
If you're calling realloc initially (rather than malloc), you need to make sure the input pointer is initialised to NULL
int *array = NULL, x, *p;

> while(fscanf(fp, "%i", &x))
Try
while(fscanf(fp, "%i", &x) == 1)
Not only does this store only valid conversions, it also doesn't loop forever when it reaches EOF