To write robust code, always treat the file pointer as a conditional gatekeeper:
#include int main() { FILE *stream = fopen("data.txt", "r"); // 1. Check for NULL before using the stream if (stream == NULL) { perror("Error opening file"); return 1; } char name[50]; int age; // 2. Use the fscanf expression in a loop or condition // This ensures you successfully read both items while (fscanf(stream, "%49s %d", name, &age) == 2) { printf("Read: %s, %d\n", name, age); } fclose(stream); return 0; } Use code with caution. Copied to clipboard 5. Summary Instant crash (Segfault). Stream is Valid but Empty: fscanf returns EOF . Fscanf C Expression Stream Null
Calling fscanf in C with a NULL stream pointer is a classic recipe for a . If you’re debugging an expression where fscanf is failing or behaving unexpectedly around null values, 1. The Anatomy of the Crash The prototype for fscanf is: To write robust code, always treat the file