Temporary file in C: solved exercise with tmpfile

Temporary file in C: solved exercise with tmpfile

This exercise is scheduled for daily publication and follows the standard site structure: statement, solution, and expected output.

Problem statement

Solve the practical case and verify the console output.

C solution

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#include <stdio.h>

int main(void) {
    FILE *f = tmpfile();
    if (!f) return 1;
    fputs("hola temporal", f);
    rewind(f);

    char buf[32];
    fgets(buf, sizeof(buf), f);
    printf("%s\n", buf);
    fclose(f);
    return 0;
}

Expected output

1

hola temporal

Common mistakes

  • Not validating standard-function return values.
  • Ignoring edge cases for indices, pointers, or buffers.
  • Skipping example-based test runs before publishing.

Practical use

Temporary files are used in compilers, text editors, and systems that need secure intermediate storage.

Guided practice and full book

If you want a complete path with progressive difficulty:

FAQ

Is this exercise useful for C exams and technical interviews?

Yes. It targets patterns that commonly appear in practice assignments, technical interviews, and C programming exams.

Where can I keep practicing with more solved C exercises?

In Programming in C in 100 Solved Exercises and C Exercises. Kindle Unlimited: View on Amazon.

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.