ch8/8-02_stdlib-fopen-and-fillbuf.c


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#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

/* The C Programming Language: 2nd Edition
 *
 * Exercise 8-2: Rewrite `fopen` and `_fillbuf` with fields instead of explicit
 * bit operations. Compare code size and execution speed.
 *
 * Notes: This file uses the standard library exclusively, in contrast to the
 * partial replacement solution in the other 8-02 files.
 *
 * The resulting binary of this file executes in about 0.001s, just like the
 * partial replacement solution. Its binary is 1KB smaller, however.
 */
int main() {
	FILE *fp = fopen("8-02_fopen-and-fillbuf.c", "r");
	if (fp != NULL) {
		puts("We could read the file.\n");
		/* pro tip: don't declare this as 'unsigned' or you'll create an
		 * endless loop thanks to EOF typically being negative. Don't waste
		 * half an hour on a newbie mistake like I did. :)
		 */
		char c;
		while ((c = getc(fp)) != EOF) {
			putchar(c);
		}
	} else {
		puts("Could not open file for reading.");
	}
	return 0;
}