すんませんでした

int main(void) {
    int i, column = 0;
    FILE *fin, *fout;
    if((fin = fopen("in_file", "r")) == NULL) return 1;
    if((fout = fopen("out_file", "w")) == NULL) return 1;
    while(fscanf(fin, "%d", &i) > 0)
        fprintf(fout, "%12d%s", i, ++column % 5 ? "" : "\n");
    fclose(fout);
    fclose(fin);
    return 0;
}