fseek and ftell in C: solved exercise

fseek and ftell in C: solved exercise

If you are looking for fseek and ftell in c: solved exercise, here is a practical, compilable example focused on the reusable idea behind the exercise.

Problem statement

Write abcdef into a temporary file, measure its size, and then read the third character.

C solution

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#include <stdio.h>

int main(void) {
    FILE *f = tmpfile();
    if (!f) {
        return 1;
    }

    fputs("abcdef", f);
    fseek(f, 0, SEEK_END);
    printf("%ld\n", ftell(f));
    fseek(f, 2, SEEK_SET);
    printf("%c\n", fgetc(f));
    fclose(f);
    return 0;
}

Expected output

1
2

6
c

Common mistakes

  • Not testing edge cases such as small or empty inputs.
  • Not validating indices, pointers, or limits carefully enough.
  • Copying the mechanics without understanding the general pattern.

Practical use

This pattern is common in CLI tools, simple persistence, and record processing.

Guided practice and full book

If you want a complete path with progressive difficulty:

FAQ

Is this exercise useful in practice?

Yes. It is designed to teach a reusable C pattern rather than a one-off toy example.

How should I practice it better?

Change the input data, add edge cases, and rewrite it from scratch without looking at the solution.

How should I practice this exercise type to improve faster?

Start with small inputs, run edge cases (empty, one item, max capacity), then rewrite the solution from scratch without copying.