How to use index in the file name

Question

This is probably trivial question. I am not a professional programmer, I am rather a mathematician who is doing some numerical experiment using C. I would like the output of my

Answer 1

In C, use snprintf:

char buf[PATH_MAX];
snprintf(buf, sizeof(buf), "file%d", i);

If you use linux, there is a useful GNU extension:

char *name;
asprintf(&name. "file%d", i);

You need to remember to free(name) after use.

Note that your syntax FILE *f(i); is not valid though.

If you need to declare an array of FILE * of 10 elements do:

FILE *array[10];

then use it like that:

array[i] = fopen(filename, "W");