Test case demonstrating correct behaviour.

fgets.c (text/plain), 655 bytes, created by Nick Bowler on 2007-06-17 06:04:10 UTC

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(void)
{
	FILE *f;
	char buf[1]; /* Change 256 to 1, and you can see the wierd behaviour
	                * of fgets if run against glibc-2.3.5 */
	unsigned lines = 0;

	/* Create this file before starting! */
	f = fopen("/tmp/null_file", "r");
	if (!f) {
		perror("fopen");
		return EXIT_FAILURE;
	}

	while (1) {
		if (!fgets(buf, sizeof buf, f)) {
			if (feof(f))
				puts("End of File");
			else if (ferror(f))
				puts("Error");
			else 
				puts("Wierd behaviour");
			break;
		}

		if (strchr(buf, '\n')) {
			printf("Read %u lines.\n", ++lines);
		}
	}

	fclose(f);
	return 0;
}