Opening and Closing Files in C

Opening and Closing Files in C — a practical guide to C fopen fclose with clear examples you can reuse in real projects.

C Programming Tutorial Series (74/102). Prefer one article? Read the complete C programming tutorial.

Short description

Modes include "r", "w", "a", and binary variants like "rb".

fopen/fclose

FILE *fp = fopen("data.txt", "r");
if (!fp) {
    perror("fopen");
    return 1;
}
fclose(fp);